This effect was devised by Billy McComb, as per McComb’s Magic 1972. The performer passes a white hank through his closed fist where it emerges a bright red. Then the performer decides to let the audience in on his little swindle. He uses two hanks!
He now demonstrates how they can go home and amaze their friends, but something goes wrong and the silk hank comes out dyed half and half—half red, half white! Not to worry, says the performer, because you need real magic to get out of this one, and he slowly passes the half-dyed hank through his hand and it emerges all red!
The audience finds that he has been fooling them all the time and they really never did learn how the hank changed colors. Comes complete with all the necessary props—15-inch silks and detailed professional instructions.