Arcane Signet

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

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Loyal Warhound

Vigilance
When this creature enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Boros Signet

Fractured Powerstone

{T}: Add {C}.
{T}: Roll the planar die. Activate only as a sorcery.

Sol Ring

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Three Dog, Galaxy News DJ

Whenever you attack, you may pay {2} and sacrifice an Aura attached to Three Dog. When you sacrifice an Aura this way, for each other attacking creature you control, create a token that's a copy of that Aura attached to that creature.

Star Compass

This artifact enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.