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

The performer has a red rubber band in his hand. The color of the band will change slowly after the finger crosses the band.

• Only use ONE rubber band to complete the color change
• No angle limitation
• Reset immediately
• No thread or other device
• Multiple routines

• Two gimmicked rubber band
• Five normal red rubber band
• Five normal yellow rubber band