Devoid

Devoid is a characteristic-defining keyword ability which states that a card is colorless, regardless of the colors in that card's mana cost.

Description
Devoid was introduced in Duel Decks: Zendikar vs. Eldrazi‎, as a preview for Battle for Zendikar‎. Because it is a characteristic-defining ability, cards with devoid are colorless at all times, including when not on the battlefield or outside of the game. However, devoid does not change a card's color identity, which is defined as the combination of all colors indicated on the card.

While functionally colorless, cards with devoid are numbered according to the color of their mana cost.

Eldrazi Displacer is the only card with devoid that has white mana in its mana cost. According to Mark Rosewater, several white-costing devoid cards were planned for Battle for Zendikar and Oath of the Gatewatch, but they ended up scrapped due to "running out of room."

In retrospect, Rosewater also said that naming Devoid was a mistake. He thought that it should have just been the reminder text as rules text with no illusion that it was a mechanic. Later, he thought it could better have been a supertype rather than a mechanic.

Rulings

 * Cards with devoid use frames that are variations of the transparent frame traditionally used for Eldrazi. The top part of the card features some color over a background based on the texture of the hedrons that once imprisoned the Eldrazi. This coloration is intended to aid deck building and gameplay.
 * A card with devoid is not the colors in its casting cost. It is treated by the game as a colorless object.
 * Other cards and abilities can give a card with devoid color. If that happens, it is no longer colorless, but it still has devoid.
 * Devoid works in all zones, not just on the battlefield.
 * If a card loses devoid, it will still be colorless. This is because effects that change an object's color (like the one created by devoid) are considered before the object loses devoid.
 * For the same reason, if a colored object gains devoid, it will still have its original color(s). It will not be colorless.