New colors without shooting lasers into your eyes

by zdw • 1 year ago

568 173 1 year ago

kadoban• 1 year ago

I am curious how these work for people with common kinds of colorblindness. The author mentions at the end that they likely don't work for that case, but they don't seem to have spent much time thinking about it.

Would it be possible to generate ones that _would_ work for specific kinds of colorblindness? Or is the entire concept doomed due to the specific way(s) that colorblind eyes are messed up?

kookamamie• 1 year ago

The animation worked for me, I'm red-green colorblind.

qayxc• 1 year ago

The red inside, reddish-orange outside was a little strange - I'm not colour blind, but have a really hard time distinguishing shades. As soon as I focused on the white dot, the red circle started to blend with the background and disappeared completely (was just one single colour for me). Only when it started shrinking did I hallucinated a faint green aura around it until it was gone.

dentemple• 1 year ago

I have deuteranomaly, and the hallucination worked for me, and it did appear like a crazy saturated blue-green ring around the shrinking red circle.

I suspect, however, that those of us with deuteranomaly probably see a different blue-green than normal-sighted folks due to the bent color cones.

The real question is, what about the folks with Deuteranopia (no working green cones at all)?

Deuteranomaly, though, is still probably the best place to start since that's the big one that affects (some say) up to 10% of all males. Every other form of colorblindness affects a much slimmer percentage of the population.

tricolon• 1 year ago

I have red-green weakness but only saw a lighter green around the circle as it became smaller.

saagarjha• 1 year ago

I saw this as well.

tgv• 1 year ago

Didn't work for me. I notice that the color around the circle changes, but it's just a palish blue-something, not a new color, certainly not intense. Too much overlap, I guess. Perhaps it works when changing the background to blue?

I fail on the first page of the Ishihara (?) test. When using those colorblindness filters in photoshop/-like apps, the protanopia and deuteranopia filters do very little for me. No 'real' diagnosis. I can see red and green though, but the shape needs to be big, and the color should be quite saturated. Reading resistors is really hard.

osamagirl69• 1 year ago

It is incredible to see a concept going from 'optical table of sensitive equipment fraught with numerous safety concerns' to 'here is a 1 kB svg animation, stare at it for 1 minute' in 3 months.

Enjoy your forbidden color, you earned it!

layer8• 1 year ago

The article however concludes: “So do the illusions actually take you outside the natural human color gamut? Unfortunately, I’m not sure. I can’t find much quantitative information about how much your cones are saturated when you stare at red circles. My best guess is no, or perhaps just a little.”

zahlman8• 1 year ago

FTA:

The idea for that animation is not new. It’s ~~plagiarized~~ based on Skytopia’s Eclipse of Titan optical illusion (h/t Steve Alexander), which dates back to at least 2010.

armchairhacker• 1 year ago

This is really cool. Tangentially, it's an example of an important life lesson, "work smarter not harder". To see the impossible color, you could build a super-expensive, super-complicated laser to directly stimulate the exact cells; or you could desensitize the other ones with an optical illusion that works on a personal device (effectively zero cost and minimal complexity since it uses existing technology).

Not to say the laser is a waste, despite the above I'd argue it's very useful. It lets us test how effectively the above actually works, and has other applications.

do_not_redeem• 1 year ago

This optical illusion isn't some brand new thing. It's been widely known since I was a child, and surely hundreds of years before that.

The laser system results in a stronger perceptual effect than you get from the illusion alone. We didn't have the technology to build it until recently. I'm certain the people who built it knew about the illusion, and it's probably what inspired the experiment in the first place.

fortyseven• 1 year ago

That is a notion that is far easier to make in hindsight.

gcr• 1 year ago

What is the animation supposed to be like? I see just a black bar on the left narrowing, but nothing else happens. The red circle and green background and white dot didn’t change. (iOS 26 beta, iPhone 15)

satellite2• 1 year ago

After the black bar finish narrowing the red circle gets smaller slowly

gpderetta• 1 year ago

After the black bar disappears, the circle start shrinking and on the boundary you can indeed an intense azure/green colour.for me quickly flickering the eyes left and right did temporarily increase the patches of intense colour.

solardev• 1 year ago

It's not the animation itself that does anything magical, but the afterimage (I think that's what you would call it?) your eye produces after you stare at the dot for long enough. The black bar is just a countdown timer for the impatient.

But try to maintain laser focus on the central dot, not letting your eyes move or blink if you can help it. Once the black bar depletes, the circle should start shrinking, and around its periphery (like an eclipse) should be some incredibly vivid, super saturated colors.

gblargg• 1 year ago

The bar is counting down time to wear out the receptors in your eye (you need to be staring at the center the whole time). THEN the illusion begins.

fabiospampinato• 1 year ago

Now we need to know from the people that experienced the laser how different this hallucination feels compared to that. Very cool stuff!

sampl3username2• 1 year ago

Using psychedelics, specifically 2C-B and LSD, you can also see very saturated colors you don't normally see in daily life. I see very saturated magentas.

louthy2• 1 year ago

I wonder how much of this is ‘seeing’ and how much is emergent in the brain due to the drug. I suspect the latter, but that’s just opinion.

dr_dshiv3• 1 year ago

“how much of this is ‘seeing’ and how much is emergent in the brain”

Yeah… it’s gonna be hard to distinguish those in the best of circumstances.

sampl3username2• 1 year ago

Seeing is also an illusion by the brain, all colors are in your head.

neom• 1 year ago

Everything is quite intense that way with 2C-B, very very rich, but in a more psilocybin way than LSD. 2C-B is super weird, I find it hard to pinpoint what it is about 2C-B that is so unique among the phenethylamines/tryptamines.

_Microft• 1 year ago

Open the experiment animation and refresh the page multiple times to refresh the countdown while looking at the white pixel (from the same point of view) to get an even more impressive effect.

TheAceOfHearts• 1 year ago

To me it looked like the circle outline had a shimmering aura, it felt very magical. This was a incredibly delightful experience so I just want to say thanks for posting it.

When the circle was around the halfway point of shrinking the color looked the most vivid for me, so be sure to wait the whole duration.

bozhark• 1 year ago

Similar, an extremely bright and magnificent teal-ish green with a vibrant yellow edge was dancing around the edge of the circle

soared• 1 year ago

You can also look at the background about halfway through and get a large circle of the new color, the same size as the original circle.

AlphaAndOmega0• 1 year ago

To me, it seemed to be a visual equivalent of that auditory trick where a note seems to descend or ascend in pitch indefinitely. The outer aura of color seemed to be shrinking constantly.

drcongo• 1 year ago

The Shepard Tone - https://en.wikipedia.org/wiki/Shepard_tone - brilliantly used by Hans Zimmer in the Dunkirk score.

isoprophlex• 1 year ago

At the end, the green circle had a very intense grainy, hypersaturated quality for me. Not like the shimmering aura that shrinks with the red circle, but still there was something magical going on.

I looked away, and then back to the screen, and the effect was gone. It was only in my head. Wow.

A super fun, delightful experience indeed.

renewiltord• 1 year ago

I, too, had this view. It was flecked with blue. Like a linen sheet it had those lines.

fivestones• 1 year ago

I looked away, then back, and the effect was gone—but then reappeared after a second or two, only less pronounced.

uncircle2• 1 year ago

The aura was a very brilliant green, which reminded me of an hallucinogenic experience I had. I was sat with friends in the city centre, my brain altered by chemical substances, and I spotted a guy 100m away with the most brilliant and beautiful green shoes. It was an amazing sight, standing out from everything else.

Sober, I later realised that they were normal green shoes, but in my no-brain-filter state, I was able to appreciate that we have many more green cones in our retina than red or blue, and normally the mix dial for green in our brain is kept pretty low not to overpower the other colours. The animation once again raised this dial to show how powerful is our raw perception of that colour.

(The evolutionary reason is that we spent a lot of time in vegetation or on trees, and it's very useful to be able to distinguish things and perceive small movements in a sea of green.)

jtr1• 1 year ago

Yes, this reminded me of a similar experience camping with friends where we could only describe the foliage as “ultragreen”. An incredibly vivid blue-green tone that suffused the whole island where we were staying. Been looking for explanations since

Cthulhu_• 1 year ago

The one with a red circle on a brown background had a really interesting effect; before the circle starts to shrink, the background becomes the same colour as the circle, then moving your eyes made a bright red or green circle appear, each on their opposite side.

nartho• 1 year ago

Do you have red-green color blindness ? The background is clearly green.

Edit : Apologies, I just now see the other ones.

rcxdude• 1 year ago

I got that, as well as a seemingly random set of changes in apparent brightness. The Magenta one seemed to produce patches of bands in my vision as well, think like blown up versions of edge detection kernels.

chakintosh• 1 year ago

Same thing for me, although, it looked more like an aura rotating around the red circle with a cyan-ish glow with a hint of teal.

NL8073• 1 year ago

As the circle was about to disappear, the blue-green was super saturated for me and persisted for a good minute if I kept locking onto the white dot. Another thing you can do, is at night time (lights off) look at the red circle like before, and when the timer runs out close your eyes and keep it dark. You will see blue-green glow very strongly.

blurbleblurble2• 1 year ago

Serious pleasure

tanepiper• 1 year ago

Interesting colours coming out of it - a while back I suspected I have https://en.m.wikipedia.org/wiki/Tetrachromacy since I was able to describe colours more vividly that others, and certain plants for me like Verbena have a glow around them.

Aardwolf• 1 year ago

I'd love it if there was someone with tetrachromacy who also knows a bit about color theory and perception and can talk about it!

How do you describe the experience scientifically? Do you get a whole bunch of extra colors you'd want to give a distinct name since they're so clearly different from the standard trichromatic colors?

Is a computer screen annoying because it can only produce a subset of the colors you can see?

Do you notice that you have a fourth parameter or dimension in the colors you see, so would want a 4th component in RGB, HSV, etc... color sliders? E.g. for our HSL, would the fourth parameter be hue-like, saturation-like, lightness like or some completely novel other thing? If hue like, do the hues also form a 2D sphere or torus like topology similar to how our trichromatic hue forms a circle?

I'd expect at least twice or 3x as many named colors, since for every regular color (red, green, blue, yellow, orange, purple, pink, grey, brown, black, white, ...) , you'd have a fourth dimension altering it that can be low, medium or high in value ...

E.g. for our yellow, you'd have yellow with not the extra signal, a bit of the extra signal or lots of the extra signal. Is this the case or not? Perhaps the overlapping reduces it, but as said in the article trichromats also have overlap yet we definitely see a lot more distinct colors than dichromats.

dr_dshiv3• 1 year ago

You can ask this lady: https://concettaantico.com/

dr_dshiv3• 1 year ago

Some people with two X chromosomes have this ability. And all birds.

If you are bored, try to get Gemini/claude to make a color wheel for birds or tetrachromats.

An aside: Recently I learned that birds are reptiles. That hurt my brain and I’m still recovering. Especially since the modern dinosaur exhibit claiming this fact contradicted the 1980s era reptiles exhibit down the hall (both at the British museum).

nocoiner• 1 year ago

What are birds? We just don’t know.

im3w1l3• 1 year ago

I think I would make a color triangle, except I would remove blue from it, and instead have the corners be three different colors in the red-green part of the spectrum. I guess 530, 545, and 560nm.

zahlman8• 1 year ago

Do tetrachromats have the same three "standard" cones plus a fourth? Or are they all shifted around?

nvch• 1 year ago

It's enough to stare at anything for a few minutes without moving eyes to get similar effects and hallucinations.

We see with good resolution only a small part of our visual field. Perhaps the brain starts to "invent" what's there it we don't give it information by constantly moving eyes.

As a more advanced version, they say that fire kasina practice may produce very interesting visual effects.

juliushuijnk• 1 year ago

To get 'speed up' the effect, move your face close (to the red) then away from your screen.

georgecmu• 1 year ago

For whatever reason, evolution decided those wavelengths should be overlapping. For example, M cones are most sensitive to 535 nm light, while L cones are most sensitive to 560 nm light. But M cones are still stimulated quite a lot by 560 nm light—around 80% of maximum.

The reason is simple: genes coding the long wave opsins (light-sensitive proteins) in these cones have diverged from copies of the same original gene. The evolution of this is very interesting.

Mammals in general have only two types of cones: presumably they lost full color vision in the age of dinosaurs since they were primarily small nocturnal animals or lived in habitats with very limited light (subterranean, piles of leaves, etc.) Primates are the notable exception, and have evolved the third type of cone, enabling trichromatic color vision, as a result of their fruitarian specialization and co-evolution with the tropical fruit trees (same as birds, actually).

So, what's interesting is that New World and Old World primates evolved this cone independently. In Old World primates the third cone resulted from a gene duplication event on the X chromosome, giving rise to two distinct (but pretty similar) opsin genes, with sensitivity peaks at very close wavelengths. As a note, because these genes sit on the X chromosome, colorblindness (defects in one or both of these genes) is much more likely to happen in males.

New World primates have a single polymorphic opsin gene on the X chromosome, with different alleles coding for different sensitivities. So, only some (heterozygous) females in these species typically have full trichromatic vision, while males and the unlucky homozygous females remain dichromatic.

Decent wikipedia article on the subject: https://en.wikipedia.org/wiki/Evolution_of_color_vision_in_p...

Types of opsins in vertebrates: https://en.wikipedia.org/wiki/Vertebrate_visual_opsin

im3w1l3• 1 year ago

So, only some (heterozygous) females in these species typically have full trichromatic vision

Wow that's wild how heterozygousity can be that helpful. Makes you wonder if there are other genes like that.

rozab• 1 year ago

Some human females have functional tetrochromatic vision.

https://jov.arvojournals.org/article.aspx?articleid=2191517

andyfilms1• 1 year ago

This is a good biological explanation. The physical explanation is, if the sensitivities didn't overlap, our spectral sensitivity would not be continuous. There would be valleys of zero sensitivity between the cones, and a continuous wavelength sweep would result in us seeing black bands between colors.

aetherson• 1 year ago

Gray bands, or more realistically just desaturated bands. There'd still be sensitivity to light through rods (black and white), and even if the peaks of wavelength sensitivity were highly separated there would still be some cone response to wavelengths that didn't stimulate them strongly.

__MatrixMan__5• 1 year ago

This is only tangentially related, but I have always wondered why chlorophyll absorbs blue and red, but reflects green--green being sunlight's brightest component.

It's almost as if there was some evolutionary pressure towards being very visible in sunlight which is more important than evolving ways to collect as much sun energy as possible. When I guess at this I end up with something along the lines of reflected green being used as a signal to a neighboring plant: "I'm already here, grow in some other direction instead." There is some evidence that plants do this (https://en.wikipedia.org/wiki/Crown_shyness, https://onlinelibrary.wiley.com/doi/10.1111/1365-3040.ep1160...) but it's not clear that the need to do so is so strong that it would overshadow the drive to collect as much energy as possible.

Or perhaps there's something to do with the physics of absorbing light to drive a chemical reaction that makes it better to absorb at red and blue while passing on green (450nm and 680nm are not harmonics--so if this is the case it's more complex than which sorts of standing waves would fit in some chemical gap or other).

amelius3• 1 year ago

Red is nature's warning signal, and blue was already taken by the sky, so the only option left was green.

Just kidding of course, it is an interesting question.

pinkmuffinere• 1 year ago

This is fascinating, I’d never realized there is this seeming-paradox! Thanks for mentioning it

privatelypublic2• 1 year ago

Have you looked into band-gaps?

Also remember that these are random processes with selection pressure keeping those who survive to reproduce. Assigning a will to such processes makes them and the results harder to understand- imho.

Theres probably something more efficient at converting light into simple sugars.

cheschire• 1 year ago

Maybe it was in response to an extinction level event that filtered sunlight for a long time, removing green but allowing primarily only blue or red.

o11c• 1 year ago

It could also be to prevent overstimulation; "maximize energy" is not really the goal. A lot of plants can die from too much Sun unless their other inputs are just right (plenty of water, etc.).

NoImmatureAdHom• 1 year ago

Here's a recent take: https://www.quantamagazine.org/why-are-plants-green-to-reduc...

TLDR: Plants are running an energy-harvesting system that can only respond so quickly to changes in light input. Making use of green would cause variance to be large enough that the gains would not offset the losses. So, avoid green and have lower variance --> higher energy capture on average.

cornstalks2• 1 year ago

green being sunlight's brightest component.

It actually peaks between magenta and blue: https://sunwindsolar.com/blog/solar-radiation-spectrum/

Green is only bright to us because of our cone sensitivities overlapping.

gettingoverit• 1 year ago

something to do with the physics of absorbing light to drive a chemical reaction

Exactly that. Blue does two steps of the process, while red does only one. There's a cost for synthesizing all that machinery, so absorbing green would just be not worth it.

450nm and 680nm are not harmonics

In fact they're in 3:2 ratio with 1% margin. But they don't have to be. Take a look at fluorescence: it converts one wavelength to another, and they don't have to be multiples of each other. Once photon gets absorbed onto a chemical, the electronic structure of the molecule decides what will happen to it.

adrian_b3• 1 year ago

Chlorophyll a, which is the pigment that actually uses solar energy to split water, absorbs red light and violet light. Thus its color is blue-green, as it can be seen in some lichens that have only symbiotic cyanobacteria.

This is most likely a historical accident, with no special meaning.

Most algae and plants have auxiliary pigments, which absorb other parts of the solar spectrum and then transfer the energy to chlorophyll a.

The land plants and the green algae use mostly chlorophyll b as auxiliary pigment, which absorbs light in a blue band adjacent to the violet band of chlorophyll a, and in a red band that is distinct and adjacent to the red band of chlorophyll a.

Thus the addition of chlorophyll b increases considerably the amount of captured energy.

The algae that are dominant in oceans, e.g. diatoms and brown algae, have more auxiliary pigments, so that many are dark brown, even close to black.

Unlike for marine algae, for land plants, capturing more solar energy is not desirable, because they already have difficulties in avoiding overheating and excessive loss of water. So the pigments used by them are good enough for their needs.

vikramkr• 1 year ago

There's also a chance that the primary photosynthesiizers on each happened to be purple for a while (purple earth) and the ancestors of plants absorbed red/blue and ignored green because they were getting leftovers. Also, even now, iirc the limiting step in oxygenic photosynthesis is by far rubisco's incorporation of CO2, so there's no immediately obvious fitness function that would be optimized by just increasing the efficiency of light harvesting.

dr_orpheus• 1 year ago

There was a proposed theory on this the spread of absorption created more stability in the power generation of plants over different conditions. This was supposed to be a more important factor than being able to absorb the peak and highest energy.

https://www.science.org/doi/10.1126/science.aba6630

zeckalpha• 12 months ago

I didn't see any mention of this so thought I would add:

This sounds like https://en.wikipedia.org/wiki/Retinal and https://en.wikipedia.org/wiki/Purple_Earth_hypothesis. Going through history, there have been times where the Earth has had oxygen spikes https://en.wikipedia.org/wiki/Geological_history_of_oxygen (Examples https://en.wikipedia.org/wiki/Great_Oxidation_Event or https://en.wikipedia.org/wiki/Neoproterozoic_oxygenation_eve...) Cool image showing how this process is unstable: https://en.wikipedia.org/wiki/Great_Oxidation_Event#/media/F...

You might be interested in the different photosynthesis cycles: https://en.wikipedia.org/wiki/C3_carbon_fixation https://en.wikipedia.org/wiki/C4_carbon_fixation https://en.wikipedia.org/wiki/Crassulacean_acid_metabolism https://en.wikipedia.org/wiki/Alarm_photosynthesis - this one was only discovered in 2016!

Research into these may have profound impact on climate change.

cyborgx7• 1 year ago

I'm pretty sure that line of the article didn't mean to imply that we don't know, or aren't sure, only that it goes beyond the scope of the article and isn't directly relevant to the topic at hand.

ComplexSystems• 1 year ago

Is this just my device, or is there no way to use this roll-your-own SVG generator to actually roll your own? I can only pick from a tiny subset of preset colors, most of which seem super random and desaturated and not what I want. There's no FFFF00 yellow, for instance. Is there some way to enter an arbitrary RGB color that I am not seeing? If not, why on Earth write such an interesting article, advertise this custom SVG generator and then build the interface that way? :/

altairprime• 1 year ago

Does tapping on the horizontal color box to the right of the sentence “Select any color” under heading “Inside Color (Circle)” open a color picker? If not, perhaps your browser has a defective <input type=color> implementation, i.e. Firefox for Android [1796343]?

vintermann• 1 year ago

Telenor's net nanny (which I didn't ask for) has decided that dynomight.net is dangerous and DNS blocked it.

DavidVoid• 1 year ago

Ran into the same thing. Changing to a non-default DNS fixed it.

perching_aix5• 1 year ago

So change your router settings to offer a different default DNS via DHCP? Maybe configure your device(s) to use some other specific DNS servers rather than the ones offered via DHCP?

For the site operator: the domain is present in the Spamhaus DBL (Domain Block List), which is presumably why these lovely gents are having issues, might wanna check that out.

dynm• 1 year ago

Thanks for pointing this out. I submitted a request to spamhaus but it's an auto-responder black hole that tells me to contact my "IT department". (My personal blog, oddly enough, does not have one.) They don't explain why this domain which has no ads, sells nothing, and never sends email would be listed.

lubujackson• 1 year ago

Cross your eyes like a magic eye image when it's shrinking and the vivid color will expand to a larger patch.

pixelpoet• 1 year ago

Incidentally the linked Skytopia page is that of Daniel White, who originally described the Mandelbulb: https://www.skytopia.com/project/fractal/mandelbrot.html / https://www.skytopia.com/project/fractal/mandelbulb.html

weinzierl• 1 year ago

"If you’re colorblind, I don’t think these will work, though I’m not sure."

Should work for anomalous trichromats (by far the majority of people with color deficiencies) but probably with less intensity.

"Folks with deuteranomaly have M cones, but they’re shifted to respond more like L cones."

I don't think this is true. What would the difference between deutan and protan then be?

"Why do you hallucinate that crazy color? I think the red circle saturates the hell out of your red-sensitive L cones. Ordinarily, the green frequencies in the background would stimulate both your green-sensitive M cones and your red-sensitive L cones, due to their overlapping spectra. But the red circle has desensitized your red cones, so you get to experience your M cones firing without your L cones firing as much, and voilà—insane color."

I think only people with missing L cone (Protanopia) or M cone (Deiteranopia) would not experience the phenomenon at all.

Maybe this could be used as a new type of color deficiency test?

bluGill• 1 year ago

I didn't see anything, probably because my M cones were also saturated more than a normal person. (though it is also possible I did it wrong?)

peterisza2• 1 year ago

A bit unrelated but I found this interesting: water is transparent only within a very narrow band of the electromagnetic spectrum, so living organisms evolved sensitivity to that band, and that's what we now call "visible light".

http://hyperphysics.phy-astr.gsu.edu/hbase/Chemical/imgche/w...

dennis_jeeves2• 1 year ago

Interesting, given that most life is water based, most life will respond the most to this spectrum.

andyferris• 1 year ago

Given the fluid inside your eyeball is mostly water, this is probably very related.

It’s interesting (kinda optimal) that different cones explore near both edges.

doubleunplussed2• 1 year ago

I thought it was mostly that those are the wavelengths output out by the sun.

But I guess it could be both.

davrosthedalek• 1 year ago

The sun is very close to a black body radiator, so all wavelength. The atmosphere and water filters a lot.

It is actually quite strange that plants are green -- that's the wavelength the atmosphere lets through particularly well, so would be particular good to be absorbed instead of reflected, for energy production. It seems nature hasn't come up with a good, cheap way to move the absorption into that wavelength.

Terr_2• 1 year ago

I like to joke that while nitrogen gas is the most common thing around us, we are blind to it. Of course, that's a feature, since it allows us to perceive everything else further away, instead of stumbling through a perpetual fog.

This location-dependent tradeoff is something to think about when it comes to "false color" images in astronomy. If some aliens described Earth as "a boring uniform nitrogen-colored ball", we'd probably be a little offended at their ophthalmo-centrism, and tell them that the fault lies in their eyes, not in our planet.

the21st• 1 year ago

Is there a camera that would show me what our world looks like through the eyes of these hypothetical aliens? Would love to see it.

cmrx64• 1 year ago

visible light is also the last octave before you hit ionizing radiation. it’s very energetic. good for harnessing in chemical processes. not so energetic that the electrons leave the party.

peterisza2• 1 year ago

A guy copied&pasted this comment to X and got 42k likes lol: https://x.com/sridatta/status/1947180254684237851

teslabox• 1 year ago

At least he gave credit to HN, so the diaspora could find the source. The article is interesting. I think more needs to be said about how our eyes perceive color w.r.t. led lighting.

rezmason• 1 year ago

I just want a display with a primary at 460nm. That's all I ask.

perching_aix5• 1 year ago

If you refused to look at the animation, it’s just a bluish-green background with a red circle on top that slowly shrinks down to nothing. That’s all. But as it shrinks, you should hallucinate a very intense blue-green color around the rim.

I do not believe I have any kind or amount of colorblindness, so imagine my surprise when extremely confused I pulled the image into MS Paint, used the Color Picker tool, and found that indeed, the background has quite a bit of blue in it.

Anyhow, I cannot reproduce the illusion cited. For me the circle just blurs out and I start seeing orange.

blincoln4• 1 year ago

If you make the outer colour yellow using the custom colour option, and the inner circle red, do you see a an aurora-green halo? Or if you make the outer circle yellow and the inner circle green, do you see a red halo?

perching_aix5• 1 year ago

If you make the outer colour yellow using the custom colour option, and the inner circle red, do you see a an aurora-green halo?

You mean this, right? https://dynomight.net/img/colors/generate.html?inside=ff0000...

The background turns green (???) eventually, kind of like as if ink started to spread across it.

Or you meant full yellow (255r, 255g, 0b) and full red (255r, 0g, 0b)?

Or if you make the outer circle yellow and the inner circle green, do you see a red halo?

I used the controls this time and made the background full yellow (255r, 255g, 0b) and the inner circle full green (0r, 255g, 0b). Also adjusted the countdown speed, I realized I wasn't patient enough to wait out the 60s before ever (but that also it didn't need to be so long).

During countdown the entire image turned green. Whenever my eyes would move a bit, I'd see either a 3D shadow depth effect or a yellow aura around the circle. When the circle started getting smaller I just saw the yellow aura. Whenever I'd drastically move my eyes, the entire background would revert to yellow, but would quickly go back to seeing green.

I don't really see them being unusually saturated though, but maybe I just don't have a good grasp on what to expect. Maxed out R/G/B or C/M/Y all strike me as super saturated from the get-go.

stouset• 1 year ago

I did see the illusion but I just did a double-take. That image looks just straight green to me. I suppose I could imagine it being greener somehow, but blue!?

I have a slight deuteranomaly. I did see the illusion. Pretty!

cortesoft• 1 year ago

Yeah, I don’t think I have any color blindness but that looked super green to me. I think I am fine at distinguishing two colors, but i am not the best at realizing the component colors I am seeing.

gitremote2• 1 year ago

It sounds like you have red-green color blindness. What result do you get when you take this test?

https://www.colorblindnesstest.org/cambridge-color-test/

perching_aix5• 1 year ago

100% accuracy, 25/25 correct. That said, some of them were extremely difficult, way more than others. Not sure if that's intentional, so I might still have color vision deficiency per se.

I also did the Farnsworth-Munsell 100 hue discrimination test, got a score of 28 on that - ideal being 0, and above 4 meaning something is amiss. So I don't really know what to make of this lol

ricardobeat• 1 year ago

I believe they are simply describing the color components, just like you don’t “see red” in a soft orange color.

Did you wait for the black bar to finish, and the circle to start shrinking? Takes a very long time. The effect happens at the edges and disappears if you remove your focus from the center dot.

I have mild achromatopsia and can see the effect in all color variants I tried.

zahlman8• 1 year ago

I pulled the image into MS Paint, used the Color Picker tool

The RGB values used are also indicated in the filename.

What you are seeing (in the static image) is normal. Have you noticed that (0, 255, 0) looks way brighter than (0, 0, 255) regardless of your monitor calibration? For the same reason, non-red images can have quite a bit of blue in them while still subjectively registering as "green".

https://en.wikipedia.org/wiki/Luma_(video)

itslennysfault• 1 year ago

Just in case... Maybe you didn't wait long enough? I saw nothing so I came to the comments expecting a lot of others to day the animation is broken. However, it turns out it's a lot slower/longer than I thought. I saw the little bar on the left shrink to nothing and thought that was it and exited, but that's just the start. The full animation is the red circle shrinking all the way until it disappears. There is no illusion until the circle shrinks quite a bit.

blincoln4• 1 year ago

I did a custom combination of yellow outer field, blue inner circle, and got a vibrant purple halo, which is not what I expected. I assumed it would be "yellow++", based on what I know about the human eye's colour sensitivity.

I didn't expect a strong effect, because the overlap between blue and red/green is so much less than the overlap between red and green, but bright purple is close to the opposite of what I expected. I'm genuinely puzzled.

dreijs• 1 year ago

That is interesting - I tried the setup you suggested and actually did see something that could be described as yellow++, with maybe a hint of gold/orange

It was also very intense, like staring into the sun. I observed this for both of the two default yellow tints that I could choose via the (Windows?) color picker

I have no idea why this would differ between individuals

Edit: link below with FFFF00 for yellow

https://dynomight.net/img/colors/generate.html?inside=0000ff...

blincoln4• 1 year ago

Thank you.

I retried it first thing in the morning, in the dark, with my phone screen at minimum brightness, and no contact lenses in, and I got the expected result - vivid gold for my original setting, vivid yellow for yours.

After putting my contacts in, under medium ambient light, with my phone screen at medium or full brightness, I get the purple ring, but now that I'm looking for it, I can see an outer ring of gold or yellow as well.

The effects is much less pronounced if I put on my reading glasses (while still wearing contacts), so I think it must be an artifact of the contact lenses, probably in combination with the conditions they're supposed to correct (nearsightedness + astigmatism), as well as age-related inability to focus on tiny details with my contacts in.

riknos314• 1 year ago

Can you share settings and/or a link so an exported SVG?

blincoln4• 1 year ago

https://dynomight.net/img/colors/generate.html?inside=0000ff... is the one I was using.

https://dynomight.net/img/colors/generate.html?inside=0000ff... was suggested by another commenter.

But as I mentioned in a parallel thread, I think the effect is caused by an imperfect optical path. Without my contacts in, there's no purple ring.

anigbrowl• 1 year ago

Painters have been aware of this distinction for years. I encourage interested readers to get a good artist's book on color or just head for your local art store and explore the differences between pthalo and viridian greens (or any of many other surprisingly different tonal clashes).

ErigmolCt3• 1 year ago

There's a reason artists obsess over their palettes

deadbabe• 1 year ago

The green I see around the red circle is exactly the color of a green traffic light bulb when lit, which has a hint of blue to it and is not actually pure green.

NL8073• 1 year ago

Yeah good catch. I see those light the same way.

zahlman8• 1 year ago

TFA does describe the actual colour as a bluish green, described as (0, 170, 85) in the filename. The expected illusory colour is quite different.

pb0602• 1 year ago

I don’t understand why you need the animation. If you point at the green background after staring the red one for a while, you can see a whole circle of the saturated color.

spragl• 1 year ago

I agree, that you dont. As far as I can tell, the effect comes from superimposing an after-image on some other image.

zahlman8• 1 year ago

You clearly demonstrated that you don't need the animation. However, it's a convenient way to keep you staring in the same place and not have to do anything else to cause the effect.

pb0602• 1 year ago

Incidentally, it’s also a demonstration that you shouldn’t use high contrast in typography. When you start the test you can clearly see the lines of text retained on your retina.

rvnx• 1 year ago

The same with MacBooks in dark mode, once you turn around you can see large horizontal lines separated at regular intervals that are maybe due to the refresh rate of the screen (or something else, if someone knows)

chromakode• 1 year ago

In my experience these are after exposures from lines of text. They get blurred together into indistinct lines because your eye focus moves between words, superimposing them.

ErigmolCt3• 1 year ago

Sometimes "crisp" quickly turns into "burned into your vision"

ErigmolCt3• 1 year ago

The part about bypassing our cone overlap with direct stimulation is wild, like hacking your brain's display settings

zahlman8• 1 year ago

My first thought was whether users of psychedelics who report seeing strange colour halos are experiencing something similar.

alkyon• 1 year ago

All of this resembles techniques of Op Art, for instance Fangor's works:

https://www.beloosesky.com/artists/wojciech-fangor

ziofill• 1 year ago

I was at a physics conference once and the RGB cable for the presentations was a bit faulty and one of the color channels wouldn’t work, and this presenter’s slides were all tinted cyan. After a bit of jiggling it finally worked and the slides went back to normal, but everyone heard an old professor on the first row go “on no, now they’re purple!”

MarkusQ• 1 year ago

You found the person who'd been looking at the presentation the whole time, and not down at their phone.

optiot• 1 year ago

The color I saw reminded me a lot of the kind I see when I close my eyes after accidentally looking at something too bright. I wonder if they could be related?

cubefox3• 1 year ago

The color (at least to me) doesn't actually look blue-green, but rather cyan-green. This "tertiary" color halfway between cyan and blue (#00FF80) is apparently called "spring green":

https://en.wikipedia.org/wiki/Spring_green

I wonder whether there is a physiological explanation for this.

zahlman8• 1 year ago

There is: https://news.ycombinator.com/item?id=44635782

cubefox3• 1 year ago

I'm talking about the newly induced color, not the one of the background.

evanb• 1 year ago

Many years ago [1] I was led to a marvelous site explaining many subtleties of human color perception, including the three cone primaries. The author called this pure-M-cone response "psychedelic aquamarine"; the page is offline but the archive has a capture [2]. I haven't seen this color referred to by that name elsewhere, but I think it's a good name.

I think I can see psychedelic aquamarine and the other cone primaries by closing my eyes and rubbing my eyelids while pressing in gently but firmly.

[1] https://news.ycombinator.com/item?id=813656

[2] https://web.archive.org/web/20160306132951/https://casa.colo...

blurbleblurble2• 1 year ago

Woah... did anyone else experience a noticeable desaturated sense of color after coming out of a couple rounds of those things? Like the world was in sepia tone?

terribleperson• 1 year ago

Not across my whole vision since I was using a phone, but yes.

a_t48• 1 year ago

If/when we get BCI that inject a UI into our central nervous system, I’m sure this will get overused. :)

modzu• 1 year ago

its turquoise

olelele• 1 year ago

This reminded me of the works of James Turell. I saw an installation where you observe the sky at dusk or dawn through a circular hole in the ceiling. The ceiling itself was illuminated with saturating colors and there were auras happening around the hole.

nurettin• 1 year ago

How is a negative afterimage "a new color"? I didn't get it. A fatigued cone will show you less, not more.

New colors without shooting lasers into your eyes

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