Opal Palace | Magic: The Gathering
Formats Opal Palace is Legal in
Official Oracle Text for Opal Palace
, : Add to your mana pool one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.
Official Rulings for Opal Palace
10/17/2013 : The color identity of your commander is set before the game begins and doesn’t change during the game, even if your commander is in a hidden zone (like the hand or library) or an effect changes your commander’s color.
10/17/2013 : If your commander is a card like Kozilek, Butcher of Truth that has no colors in its color identity, Opal Palace’s last ability produces no mana.
10/17/2013 : In formats other than Commander, Opal Palace’s last ability produces no mana.