Dido, Myr Commander

Eminence -Whenever a Myr creature you control taps for mana, add one mana of any color to your mana pool that it could produce.
{x}{w}{u}{b}{r}{g}{t}, Create {x} 1/1 colorless Myr arifact creature tokens with, "{t}, add one mana of any mana color to your mana pool. Use this mana only to cast artifact spells."