Dimir Signet

Orzhov Signet

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Sol Ring

Tawnos, Solemn Survivor

{2}, {T}: Create a token that's a copy of up to one target artifact token you control. Mill two cards.
{1}{W}{U}{B}, {T}, Sacrifice two artifact tokens, Exile an artifact or creature card from your graveyard: Create a token that's a copy of the exiled card, except it's an artifact in addition to its other types. Activate only as a sorcery.