Riddle 4: The black and white hats

The Black and White Hats 

Another classic and fantastic puzzle ...

"Three experts in logic gentlemen decided to play a strange game with five hats very similar to each other except for their color, three were black and two white. The knights  were placed in a line blindfolded, and each  got a hat chosen randomly. Then, without knowing what color was the hat he wore, the blindfold was removed.  The game was that during his turn had to guess  the color of hat they were wearing,  knowing that the game would end at the time which one of them chanced the color of your hat. The answers had to say  in a low voice so that other players could not hear it .  The first shift was the gentleman who was at the end of the row and could see the hats of the two gentlemen before him. He said one color and failed. He followed the shift of the second gentleman, who could see the first gentleman hat but not the third, who was behind him. He said one color and failed. Finally, having not successful the other players, it was the turn of the first gentleman, he could not see any hat. And then he xclamó:  « I know what color my hat! " . He said one color and hit. Why was he so sure the color of your hat ?. What was it ? ".