Despite the distinctive divide between Alliance and Horde in Blizzard's World of Warcraft, members of the same faction can still hurt each other in Arena PvP. Some wonder why there are extra green and gold colors when it's possible to just assign red and blue to either faction, and the answer roots back to the arenas.

At the WoW Forums, one gnome asked why developers didn't stick with red for horde and blue for alliance during Arena matches. He was then promptly enlightened, as Blizzard poster Bornakk came around to reconfirm another player's response.

Here's the post, verbatim:

We universally use blue to define the Alliance and red for the Horde on banners and such across the game. Using green and gold allows us to assign them to either faction while still having colors that are distinct enough that you won't get them mixed up.

True enough, we can imagine how disorienting it would be to see factions wearing opposing colors. Arenas in World of Warcraft allow intra-faction competition, making it a usual occurrence to see those of the same kin fighting each other. Painting the Horde blue in exchange of letting it kill its brothers is just harsh.