Automated Artificer

{T}: Add {C}. Spend this mana only to activate an ability or cast an artifact spell.

Arcane Signet

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

Astral Cornucopia

This artifact enters with X charge counters on it.
{T}: Choose a color. Add one mana of that color for each charge counter on this artifact.

All-Fates Scroll

{T}: Add one mana of any color.
{7}, {T}, Sacrifice this artifact: Draw X cards, where X is the number of differently named lands you control.

Graaz, Unstoppable Juggernaut

Juggernauts you control attack each combat if able.
Juggernauts you control can't be blocked by Walls.
Other creatures you control have base power and toughness 5/3 and are Juggernauts in addition to their other creature types.