The technology is there, but E Ink (the company) is steadfastly refusing to lower prices because they believe there's a market for this. Now go to Alibaba and find that you can get a flexible, full-color OLED sheet for the same price as a given size E Ink panel.
Go on eBay and buy an older NOOK device (they all ran Android) for $20, tape it to your wall, and point at your web page of choice.