The Sharpen by Alain Vachon - Trick

Show empty hands while holding a black "Sharpie" pen between your fingers. Flip it around and it magically turns to a red "Sharpie". Take a pause. Show empty hands again, flip the pen around and it turns to green. The pen can come back red, black, or green. As many times as you want. No panel move. Very Visually stunning.