Champion Sports Rhino Skin Mini Football Set Sting free hollow foam hole pattern and hollow core make the balls softer and truer in flight and on the balance. Set of 6 colors: Blue, Green, Orange, Purple, Red & Yellow. Sting free hollow foam hole pattern and hollow core make the balls softer and truer in flight and on the balance. Set of 6 colors: Blue, Green, Orange, Purple, Red & Yellow.