Arcane Signet
Artifact
: Add one mana of any color in your commander's color identity.
It started as a mere drop of water. The Magic Mirror crystallized it into much more.
Dan Murayama Scott
Throne of Eldraine (ELD)
• #331Rulings
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 {C}.
(wotc • 2020-11-10)
If you don't have a commander, Arcane Signet's ability produces no mana.
(wotc • 2020-11-10)
If you have two commanders, the ability adds one mana of any color in their combined color identities.
(wotc • 2020-11-10)
Rulings
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 {C}.
(wotc • 2020-11-10)
If you don't have a commander, Arcane Signet's ability produces no mana.
(wotc • 2020-11-10)
If you have two commanders, the ability adds one mana of any color in their combined color identities.
(wotc • 2020-11-10)