This Magic Gertie Ball changes color with touch...pale blue when warm and purple when cold. Kids love to see handprints, faceprints or other custom designs magically appear on the ball's surface. The Gertie balls slightly sticky surface makes them extra easy to throw and catch and because they are always light and gentle they are safe for indoor play. It's the only ball that travels well, simply deflate flat for easy packing. Safe for all ages. Assorted colors.