Color Changing Candle by Mr. Magic - Trick

Magician shows a picture of a white candle, which is inside a windowed envelope.
The Magician removes the card, shows both sides, and replaces it in the envelope.
The color of the candle changes to Red when he rubs the candle on the picture with a Red silk.
The Magician removes the card, shows both sides, and replaces it in the envelope.
He then rubs the picture Blue silk, and the candle changes to Blue.
The Magician removes the card, shows both sides, and replaces it in the envelope.
He then repeats this process with a Green silk and makes the candle Green.
Now, the magician picks up all three silks(Red, Blue, and Green) and rubs them on the picture of the candle, and then proceeds to uncover the candle...
Unfortunately the candle comes up White, so he then pulls out the candle from the envelope and it comes out Multi-Colored.