Design for a developer?

Here's my problem.

I'm basically a developer and math type of person (if you read any of abstract algebra posts), and I'm trying to learn design.

I can do UI design pretty well, it turns out to be quite usable and friendly and people can get around it, but, I can't get myself to design something that looks good.

Something that looks, you know, out of the ordinary.

I try colors and shades, and gradients but they all come out looking weird and I can never get them to work well together like some of these pages:

http://captaindash.com/ http://mailchimp.com/ http://joshsullivan.me/

Where can I learn to do this? I'm not saying how I can learn to make AWESOME websites, but, where can I learn to make websites can people can classify as looking "good"?