MacGregor offers regulation size and weight rubber volleyballs with nylon windings and butyl bladder construction. MacGregor hase the ultimate color management system with SIX colors! Use their system and provide each group with its own unique ball color! No more arguments about whose ball is left on the field or whose turn it is to play. If its your color, its your ball. All prism packs include one of each color: Blue, Green, Orange, Purple, Red and Yellow.