THIS VIDEO DEMO IS FROM THE MANUFACTURER:
A blue handkerchief and a green handkerchief are tied together. When you pull the hanks through your hand, they magically change to a red handkerchief and a yellow handkerchief! When you pull them through your hand again, they change back to a blue handkerchief and a green handkerchief! Can be repeated over and over instantly!
Big enough for adults- small enough for children!
This trick is also known as Double Color Changing Hank.