There are different types of colorblindness...
True, but white/black isn't one of them. Red-green is most common, but there are others.
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.
Hue test:
http://www.xrite.com/custom_page.aspx?PageID=77
