Knock Out Prediction

The magician takes out two small packets of cards from a card holder, one with a red back and one with a blue back. He places them on the table and states that they are each made up of 4 Kings and that two of these are turned face up as a prediction. Then, he asks two spectators to choose a black king and a red king. Once chosen, he spreads the cards of both piles on the table and the only two turned face up are the chosen Kings!
He continues by turning these two Kings face down and, as a second surprise, they will be seen to have a differently colored back from the other cards they are with!
Finally, as a third surprise, he turns the other cards face up and all will be blank!

Bicycle cards.
Simple and shocking.
The trick is fully automatic.

Difficulty: Beginner
Instructions