I think this trick is from Europe, but now sure. I have seen it once before, about 20 years ago, with paper instruction sheet. But I just came across it again, packaged with a DVD to teach it. No identification of the manufacturer, and the DVD is silent (no words), because the only move used in the entire routine is easily taught just bey seeing it done.
THE EFFECT: Magi repeated counts four facedown Aces from hand to hand, and one by one, the Aces turn faceup. When all four Aces are faceup, the magi again counts them and this time, on each count, an Ace turns facedown, but is flipped faceup to reveal it has also changed into a King. When all four Aces have changed to Kings, the cards are turned facedown, revealing that the blue backs have turned to four different colors of the rainbow.
The routine that is taught has the magician counting the cards to change each back color individually, but I think the quick "all-at-once" rainbow reveal is better, and it is no harder to do -- in fact easier.
The cards included are made of very thin plastic -- they flex and handle perfectly for the necessary false count. They also have interesting jumbo Ace pips (see photo).
Brand new with DVD instructions -- as mentioned, the teach-in is silent with some screen captions, and closeup hand-shots demo-ing the moves and routine.