Dan Kaminsky, an internet security researcher, had a hobbi project which turned out to be a huge success. He created a 3$ iPhone (+ Android) application which is based on augmented reality and was designed to help people with colour blindness.
There’s actually a lot of color blind people — about 10% of the population. And they aren’t all guys, either — about 20% of the color blind are female (it totally runs in families too, as I discovered during testing). But most color blind people are neither monochromats (seeing everything in black and white) or dichromats (seeing only the difference between orange and blue). No, the vast majority of color blind people are in fact what are known as anomalous trichromats. They still have three photoreceptors, but the ‘green’ receptor is shifted a bit towards red. The effect is subtle: Certain reds might look like they were green, and certain greens might look like they were red.
Thus the question: Was it possible to convert all reds to a one true red, and all greens to a one true green?
The answer: Yes, given an appropriate colorspace.
To describe it even more clearly, here is the Ishihara colour test. If you don’t have this condition, you will spot numbers in the big circles on the left. If you can’t spot those numbers, on the right, you’ll certainly spot them as here are the same pictures but through the application of Dan.