You can buy 3-color (white, black, and read all over) ones for ... I want to say about 20 yuan which is like $3? I haven't looked into driving them yet; that's

You can buy 3-color (white, black, and read all over) ones for ... I want to say about 20 yuan which is like $3? I haven't looked into driving them yet; that's step 3 and I'm still on step 1 (monochrome OLEDs) but I think you might have to do some funky temperature adjustment stuff to get good results out of them...maybe that hasn't quite been integrated into the display controller chips yet?