Blendoku may be the only colorful iPhone game that works for colorblind people; so long as they can depict lighter or darker shades. The simple game requires you to organize the different hues of a color in the right order, just as the colors would blend lighter to darker in an HTML color chart.
The game starts simple -- filling in everything in between yellow to red -- and can go up to the master level where different color palettes intertwine with common shades.
There have previously been many colorful iPhone games, but none that strictly evaluate your ability to distinguish hues of colors; you must have a good sense of color schemes and the quick reflexes to place them accordingly.
If you don't know the difference between violet and lavender and which comes first in the purple palette, the game might not be for you.