Color blindness is actually pretty frequent, affecting about one in ten men and one in two hundred women. Not well understood is that there’s quite a variety of ways it expresses — truly, it is a “spectrum disorder”.
DanKam attempts to provide a variety of mechanisms for allowing the color blind to determine colors of objects around them. Specifically, DanKam exploits rendering of alternate color spaces (HSV to start) and actively quantizing hue for canonicalization effects. It’s not perfect, but reports are that it’s surprisingly useful. It is re-entering active development and is soliciting feedback.