All nonwhite creatures your opponents control will have base toughness 0, and die as a state-based action due to having 0 toughness unless there is another effect increasing its toughness.
Whenever a nonwhite creature enters the battlefield under an opponent's control, it will have base toughness 0, and die as a state-based action due to having 0 toughness unless there is another effect increasing its toughness.
Results
Reduce each nonwhite opposing creature's toughness to zero.
Nonwhite creatures opponents control die upon entering the battlefield.