Arcane Signet
Commander Legends: Battle for Baldur's Gate — uncommon
Artifact
Arcane Signet rulings:
2020-11-10: If you have two commanders, the ability adds one mana of any color in their combined color identities.
2020-11-10: If your commander is a card that has no colors in its color identity, Arcane Signet's ability produces no mana. It doesn't produce .
2020-11-10: If you don't have a commander, Arcane Signet's ability produces no mana.