My best friend is color blind.  He does not see red or green
That would be so strange to be color blind. Can you tell me more about this disorder?
blindness is an inherited problem in the development of one or more of the three sets of color-sensing cones in the eye. Males are more likely to be color blind than females, as the genes responsible for the most common forms of color blindness are on the X chromosome. As females have two X chromosomes, a defect in one is typically compensated for by the other, while males only have one X chromosome. Color blindness can also result from physical or chemical damage to the eye, optic nerve or parts of
A's black hat and C's lack of response that he (B) is wearing a white hat.
So if A wears a black hat there will be a fairly quick response from B or C.
Assume that A wears a white hat: 
- C does not see two black hats, so he is unable to tell his hat color.
- B sees only a white hat, so he can't tell anything about his hat.
In this case A, B and C would remain silent