Painter's Servant 
Artifact Creature — Scarecrow
As this creature enters, choose a color. All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL