What are the evolutionary advantages and disadvantages of impaired color vision?
It is thought that normal trichromatic color vision provides advantages for finding healthy food and healthy mates, both of which are selective advantages for evolution. However, it is clear that people with color vision deficiencies can function quite well in the world and therefore there hasn’t been enough of a disadvantage of these deficiencies to make them fade away through evolution. There are even reports of some situations in which color deficient observers can see patterns that are masked by all the color variation that normal observers might see.
