Fallaji Wayfarer

Fallaji Wayfarer is all colors. This ability doesn't affect its color identity. (It can be in any deck whose commander's color identity includes green.)
Multicolored spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a multicolored spell pays for {1} or one mana of a color that creature is.)

Painter's Servant

As Painter's Servant enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Commandeer

You may exile two blue cards from your hand rather than pay this spell's mana cost.
Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters under your control.)

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Memnite

Grindstone

{3}, {T}: Target player mills two cards. If two cards that share a color were milled this way, repeat this process.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Etched Champion

Metalcraft — Etched Champion has protection from each color as long as you control three or more artifacts.