Here is a clever close-up effect using just four playing cards and a little hocus pocus.

You show two red Kings face up and sandwiched between two face down cards.

Magically the two red kings change to two BLACK Kings.

As your audience are trying to work out how you did it, with another magical flourish the Kings change yet again into the four Aces which can be shown on both sides – wow!

Looks like impressive sleight-of-hand but is easy to do.