Have

Arcane Signet

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

Plains

Command Tower

Selvala, Explorer Returned

Parley — {T}: Each player reveals the top card of their library. For each nonland card revealed this way, add {G} and you gain 1 life. Then each player draws a card.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.