Snow Blind by Bob Solari
Four-of-a-kind cards are shown and turned face down. The back of each cars isshown to have a Blue back. The performer asks the spectator "Which one of thecards had a Red back?" The spectator responds with "None."
Theperformer say's "are you sure, I think you may be snow blind." The performerturns the four cards face down, showing them each to ahve White backs!