Last Card - Harries

You show a sealed prediction envelope and hand a deck of cards to a spectator for examination and to shuffle. You have an elegant stand with four colored sections. Let the spectator place four cards in each section. Remove the cards from three of the sections by the choice of the spectator. Now you have only one section left with four cards. Allow the spectator to place the four remaining cards in the four different sections, remove three of them showing them all to be different. And the remaining card, the Last Card, matches of course the card in the sealed prediction envelope.
Easy to perform, yet a strong effect.