Polder Magic by Peter Pellikaan

Polder Magic by Peter Pellikaan
You show four cards blank on both sides. Suddenly one changes to a Jack of Clubs with a regular blue back. One moment later all four change to blue backs and Jack of Diamonds on the front. Barely a moment later they have all red backs and Jack of Hearts on the front. If you haven't seen enough color changes the four backs change to yet another color. The fronts are blank again with one exception, a Jack of Clubs. You end where you started with all four cards blank on both sides.