The most controversial riddle: Who can say the color of the hat he is wearing?

Answer: Mr. No. 2 will say correctly what color his hat is. Because if Mr. No. 1 sees Mr. No. 2 and No. 3 wearing different colored hats, he will not dare to say. When Mr. No. 2 sees the color of Mr. No. 3's hat, he will know what color his hat is.