Kozilek's Unsealing

A card with devoid is just colorless. It's not colorless and the colors of mana in its mana cost.

Devoid doesn't affect the color identity of the card for the purposes of the Commander variant. For example, while Abstruse Appropriation is colorless because it has devoid, its color identity is still white and black, and it can't be included in a Commander deck where the commander's color identity doesn't include both white and black.

If you cast a creature spell with {X} in its mana cost, use the value of X that was chosen when it was cast to determine its mana value.