loll if u wanna know the answer then highlight beloww :lol:
Possibilities:
2 black, 1 white => Person wearing white sees 2 black, knows he's wearing white and immediately calls out.
2 white, 1 black => Black can't say anything because he sees two white and can't tell because he could be wearing white or black. One of the whites knows that the other can't see two black otherwise he'd have called and therefore knows he's wearing white can so calls white.
3 white => since nobody is calling, any one who is bold enough can with fair certainty assume at they're all as unsure as each other because they all see white and the injection of even one black makes someone completely certain. So all tehy have to do is call white.