My friend is running a {Tristani, Selesnyas Voice} EDH deck, and were having a debate over if {Garruk Relentless} is legal because of the flip side.
The color identity counts both sides of the card.
You can see in the left side of the bubble a little black circle which indicates a black identity as the flipped side does not have a mana cost.
903.4c The back face of a double-faced card (see rule 711) is included when determining a card's color identity.
Example: Civilized Scholar is the front face of a double-faced card with mana cost {2}{U}. Homicidal Brute is the back face of that double-faced card and has a red color indicator. The card's color identity is blue and red.
Quote from: Death, the Kid on March 24, 2014, 01:00:48 PM
My friend is running a {Tristani, Selesnyas Voice} EDH deck, and were having a debate over if {Garruk Relentless} is legal because of the flip side.
It is not legal for a Trosti deck.
Elbrus the binding blade is considered black in the same respect