I was reading an article about how they may have discovered a cure for color-blindness (This was something a color-blind ENTP friend posted, actually). The article mentioned that red-green color blindness is carried on the X chromosome. This surprised me, because I knew color-blindness was "a male" thing (I didn't even know females could get color blindness"), which meant that I thought it was on the Y chromosome.
Therefore, colorblindness might be present in females, but much rarer. For this to be the case, though, it would have to be a recessive gene, since females have two X chromosomes. If it was dominant, color-blindness should be equally common in males and females.
This would also mean that if a woman who is color-blind has any male children, they must also be color-blind. A color-blind woman, must have the color-blind allele on both of her X chromosomes, because it is recessive. No matter which X chromosome they get from their mother, then, it carries the color-blindness gene, and they lack a second X chormosome to "cancel it out." Therefore, any male children will also be color-blind