Amy Winehouse, Like Smoke

Back to Black—If all creatures on the battlefield are black, Amy Winehouse, Like Smoke gains Deathtouch, Menace, and +2/+2.
{b}{b}{b}:Target creature is now black and ignores all other color types.
{b}{b}{b}{b}{b}{b}: Until the end of turn, all
creatures are now black. Ignore all other color types on creatures effected by this until the end of turn.