It's actually a paint chip sample from Home Depot. They have 2 kinds - Alien Green and Sonic Boom. The paint chip is in the form of a Mickey head.
People here would cut out the shape, stick 2 back to back, decorate it, laminate it, then punch a hole and tie a lime green ribbon on their back pack, fannypack. Or they put a pin on the back and pin it to their shirts, or put it on their ponytails, etc - anywhere that's visible.