Different-coloured monsters happily howl, growl, and roar for more as they mix and match primary colours to make new shades and hues. While everyone might know that yellow and blue make green, it has never been created in such an unusual and celebratory way! In this wild and colourful romp, small gray monsters morph into big, colourful ones as the book progresses. Never has colour been presented in such enthusiastic and exuberant style. Never have monsters been so creative and appealing.