MTG Salvation

9/22/2011 The color identity of your commander is set before the game begins and doesn’t change during the game, even your commander is in a hidden zone (like the hand or library) or an effect changes your commander’s color.

9/22/2011 If your commander is a card like Kozilek, Butcher of Truth that has no colors in its color identity, Command Tower’s ability produces no mana.

9/22/2011 In formats other than Commander, Command Tower’s ability produces no mana.