This is a CGI effect that you can achieve in reality by using just ONE rubber band.

• The performer holds a red rubber band in his hand. The color of the band will slowly change after the finger passes over it.
• Use just ONE rubber band to complete the color change
• No angle restriction
• Instant reset
• No string or other device
• Multiple routines

What do you get?

• Two gimmicked rubber bands
• Five regular red rubber bands
• Five regular yellow rubber bands