what is the probability of being colorblind
XnY one color blind boy. 1  Probability of having a color blind daughter is (1/2 x 1/2) or 1/4 or 25% (0.25) This is because both sex and colorblindness are involved in the solution.  The probability that their first son is color blind is 50% (0.50). In this question only males are part of the solution.