Dots Impossible Royal
"Six cards are placed face-down on the table. A spectator freely chooses any card. When he turns his card over, it has a red dot on it. The remaining cards are all blue. The feat is repeated. This time the spectator selects a blue card. The other five are shown to be red! It does not matter which card is selected, it is always the odd one out.
A sleightless miracle printed on Royal playing card stock.