Fool your friends with observation test they'll never pass!
Fun trick, not difficult to do, with surprising ending!
You should learn it today!
Video
Performance
Magician shows the deck to spectator and shuffles it
One card is on the table from the beginning of the trick - magician takes the card and shows that it has different color back then other cards
This card is placed on the top of the face up deck and cut
Magician spreads the deck to show that all cards changed color - the entire deck has now different color then before and the card that was on the table from the beginning changed the color as well!
Presented as observation test, spectator didn't observe the colors correctly!