Steve Mitchell-USA TODAY Sports
While black masks are not banned, the league prefers clear masks so that it is easier to see an opponent's eyes, according to Bleacher Report's Ethan Skolnick.
GIFs of James dunking and roaring in the mask went viral after his dominant performance in a blowout win against the New York Knicks, in which he put up 31 points on 13-of-19 shooting.
James, whose brand has been valued at $20 million, knows how cool he looked, especially how it matched the Heat's black throwback uniforms, a source tells ESPN's Brian Windhorst.