Fellwar Stone

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

Sol Ring

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. Talisman of Impulse deals 1 damage to you.

Trailtracker Scout

{T}: Add one mana of any color.
Whenever you expend 8, return up to one target permanent card from your graveyard to your hand. (You expend 8 as you spend your eighth total mana to cast spells during a turn.)

Bello, Bard of the Brambles

During your turn, each non-Equipment artifact and non-Aura enchantment you control with mana value 4 or greater is a 4/4 Elemental creature in addition to its other types and has indestructible, haste, and "Whenever this creature deals combat damage to a player, draw a card."

Arcane Signet

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

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Sanctum Weaver

{T}: Add X mana of any one color, where X is the number of enchantments you control.