Comment Re:Why stop there? (Score 1) 137
This is wrong, of course.
Humans have 3 unique cones. Less than 3 means some form of color blindness.
Women, by virtue of having 2 X chromosomes, have two slightly different codings for one of the 3 cones. Most of the time one is switched off but occasionally a woman may have both versions of that cone resulting in a 4th unique receptor. The difference is very minor and there is no evidence that this leads to superior color sensitivity or that their brain even realizes it has some additional information. The claim that women have better color vision is complete BS.