Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Lion's Eye Diamond

Discard your hand, Sacrifice Lion's Eye Diamond: Add three mana of any one color. Activate only as an instant.

Mishra's Workshop

{T}: Add {C}{C}{C}. Spend this mana only to cast artifact spells.

Mox Opal

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

Sol Ring

Mox Diamond

If Mox Diamond would enter, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.

Slicer, High-Speed Antagonist

Living metal (During your turn, this Vehicle is also a creature.)
First strike, haste
Whenever Slicer deals combat damage to a player, convert it at end of combat.

Slicer, Hired Muscle

More Than Meets the Eye {2}{R} (You may cast this card converted for {2}{R}.)
Double strike, haste
At the beginning of each opponent's upkeep, you may have that player gain control of Slicer until end of turn. If you do, untap Slicer, goad it, and it can't be sacrificed this turn. If you don't, convert it.

Slicer, Hired Muscle // Slicer, High-Speed Antagonist

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Commander's Plate

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander {3}
Equip {5}

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.