March of the Canonized

Your devotion to two colors is the number of mana symbols among mana costs of permanents you control that are the first color, the second, or both. If an effect counts your devotion to two colors, a hybrid symbol that is both of those colors is counted just once.

If you put an Aura on an opponent's permanent, you still control the Aura, and mana symbols in its mana cost count toward your devotion.

Colorless and generic mana symbols ({C}, {0}, {1}, {2}, {X}, and so on) in mana costs of permanents you control don't count toward your devotion to any color.