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.
What do you get?
My Rebus
Monster Spellbound by Mott Sun
Switch Cup Ash Edition by Jerome Sauloup & Magic Dream
Heal by Smagic Productions
Box Monster by Nate Kranzo
Trespassing by Smagic Productions
IncREDiBULL (Props and DVD) by Eric Buss
MIST (DVD and Gimmick) by Peter Eggink