Kozilek's Sentinel

Creature — Eldrazi Drone

Devoid (This card has no color.)
Whenever you cast a colorless spell, Kozilek's Sentinel gets +1/+0 until end of turn.

1/4

2015-08-25:
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 deckbuilding and game play.
2015-08-25:
A card with devoid is just colorless. It’s not colorless and the colors of mana in its mana cost.
2015-08-25:
Other cards and abilities can give a card with devoid color. If that happens, it’s just the new color, not that color and colorless.
2015-08-25:
Devoid works in all zones, not just on the battlefield.
2015-08-25:
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.