With just some practice everyone can pull off this card trick. At first, like most tricks it will seem a little confusing and awkward but after running through it a couple times it will become second nature, very smooth and leave your audience scratching their heads.
To successfully perform the color change trick you will need the following things:
Make sure you have one deck of cards that has a blue back and another deck of cards that has a red back and they both are the same sized cards. Select ten cards, five from the red deck and five from the blue deck, it does not matter what cards you get out.
You can begin by alternating one blue backed card and then one red backed card making five pairs of cards in your hand. Without showing the backs of the cards, fan out the face up cards and show your audience. Tell them to point to one of the cards in the pile you have fanned out. Take out the card they chose and with a little magic place it on display with it facing up so that everyone can see. Separate the cards in your hand by putting those that came in front of the selected card into your left hand and the rest in your right. Now place the cards from your left hand on top of the cards in your right hand, do it secretly when the people are looking at you drop the card on the table. Be sure not to show the backs of the cards.
The magic happens:
And now that part of the trick which will bedazzle you. Convincing your spectators that all the cards have the same color on their backs is what you must do. Make sure the cards ain a tight bundle after you have placed them back together from both of your hands. The cards are still face up. Pull the top card off and turn it over showing the back side. Once this is done mention, “The same color is on the back of each card.” As you say this you can casually turn the stack in your left hand over showing it also has a blue back. Now as you carefully place the top card and the stack of cards in your left hand in a separate pile on the table face up as you explain that the card they chose has magically changed color and it is now red on the back.
Tell the spectators that the card they chose which was once red now had a blue back on it. Turn it over for the amazing reveal. The color has changed from the selected card. Amazing!
As long as you practice this trick a few times and make sure that you stack the deck carefully without revealing the back sides too soon this trick will amaze your audience. Remember the color the people chose remains the color on the back of the card. It wont make a difference if they choose either colored card. You put the cards back into their sequenced order when the left cards were put in front of the right ones.