These cards are listed in no particular order
A card like Blighted Cataract is colorless in game, but has a blue color identity, and we're focusing on cards that could be played in a colorless Commander deck
And we haven't seen a copy up for sale since, until a recent eBay listing appeared, offering a PSA 8 graded version for some pocket change - if you have giant pockets that can hold $2,000,000 / 1,606,000 worth of change, that is
Sage's Nouliths Rarity: Common TYPE: Artifact SUBTYPE: Equipment CMC: 2 Mana cost: USD: $0.13 EUR: 0.06 TIX: 0.03 EDHREC RANK: 11469 Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.) Equipped creature gets +1/+0, has "Whenever this creature attacks, untap target attacking creature," and is a Cleric in addition to its other types
Craft with two that share a card type (, Exile this artifact, Exile the two from among other permanents you control and/or cards from your graveyard: Return this card transformed under its owner's control