Alloy Golem

Color identity, made literal. Where a creature's color is usually a fixed consequence of its mana cost, this Golem hands the choice to the controller at the moment it resolves, decoupling color from how it was cast. That sounds trivial until you remember everything in Magic that keys off a creature being a particular color: protection, color-restricted removal, anthems, lords, and the era of Invasion's gold cards that rewarded specific color combinations. A colorless artifact that announces itself as any one color slots into those frameworks on demand, which made it a quiet utility piece in five-color and multicolor builds that wanted a body able to dodge the right removal or qualify for the right pump. The chosen color is locked in as it enters, so the choice is a one-time read of the board rather than an ongoing toggle. The cost is the giveaway: six generic mana for a 4/4 with no evasion and no immediate impact is a deliberately plain rate, the price paid for a body that costs no colored mana and can pretend to be whatever the deck needs. It is a fixer's creature, the kind of card built to make an awkward manabase work rather than to win on its own merits.