Sol Ring

Llanowar Elves

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Ramos, Dragon Engine

Flying
Whenever you cast a spell, put a +1/+1 counter on Ramos for each of that spell's colors.
Remove five +1/+1 counters from Ramos: Add {W}{W}{U}{U}{B}{B}{R}{R}{G}{G}. Activate only once each turn.

Arcane Signet

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