When it comes into play, you pick a color, letting you tap it to generate four mana of that color
Brainstorm (T1, Ext, S, Block) Originally named the Poor Man's Ancestral, Brainstorm has shed that stigma and come into its own as a top-notch card-drawing card in recent years
Lets exclude all gold cards, hybrid cards, or white double-faced cards that transform into cards of other colors (sorry Brutal Cathar/Moonrage Brute)
Facilier is the exceptionally musical villain of The Princess and The Frog, using his contacts in the underworld for his own misdeeds
Ruby has been the yin to Amethyst's yang, the two inks teaming up to create the best deck in the game throughout much of Rise of the Floodborn