Fellwar Stone

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

Codie, Vociferous Codex

You can't cast permanent spells.
{4}, {T}: Add {W}{U}{B}{R}{G}. When you next cast a spell this turn, exile cards from the top of your library until you exile an instant or sorcery card with lesser mana value. Until end of turn, you may cast that card without paying its mana cost. Put each other card exiled this way on the bottom of your library in a random order.

Exotic Orchard

Command Tower

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