Also, it's interesting to note that men and women have different ratios of rods and cones in their eyes, that give women the advantage of seeing more subtle differences in colors, and give men a small advantage in low-light conditions. Of course, each individual human has a range as well, so some men see colors better than some women, etc.
Oh, and did you know that some people (mostly women) can see 4 colors?
http://en.wikipedia.org/wiki/Tetrachromacy#Possibility_of_human_tetrachromatsThis has been your useless fact of the day.
