How about presenting a miracle where a thought-of card, signed and removed from a normal deck, changes color? 

And, the deck had already been examined and shuffled by the spectator!!! 

Without any change? 

This is BRAIN WAVED: 

A new method for a miraculous effect! 

When a normal card, freely chosen (or simply thought of prior to its being removed from the deck) changes color... 

Keep in mind that everything is done under these strict conditions:

• You are using a normal deck (examinable before, during and after the trick)
• It is shuffled
• A card is chosen freely (or simply thought of prior to its removal)
• This card is taken out of the deck and signed
• The spectator can change his mind
• No force
• No accomplice
• No change

At the end of the effect, you can leave the card as a souvenir with your phone number, for example. 

In the spectator's mind, there is nothing. 

Nothing, nothing and nothing. 

Everything is clean. 

This is maybe the most magical: get such a result with all these conditions!