Quote Originally Posted by willpell View Post
Green orcs are a Warcraft invention as far as I know; D&D explicitly lists them as being gray-skinned, and I don't know of any references to the contrary in any of the published books. The Giant probably made his orcs green due to the popularity of WOW or just because he thought it looked better (it might also have been for technical reasons, similar to the Hulk in Marvel Comics having been gray for two issues and then turning green because the gray wasn't printing right).
I've always seen D&D orcs described as having grayish-green skin.