Dream Coat

Caster may change target creature's color to any other color. This ability is played as an interrupt. Limit of one change per turn. Cost to tap, maintain, or use a special ability of target creature remains entirely unchanged.

"Adopt the character of the twisting octopus, which takes on the appearance of the nearby rock. Now follow in this direction, now turn a different hue."Theognis, Elegies 1, 215