ARAM spectator mode: Purple team referred to as Red team

The clue is in the title.

Noticed this today while watching an ARAM game, Patch 5.18, English language, EUW server. A purple turret and inhibitor were destroyed, but the announcer and the notifications at the top of the screen reported a red turret and inhibitor being destroyed. There is no red team in ARAM games.

Not sure if the bug affects other events, such as team multikills or inhibitors respawning, or other language translations. It's not gamebreaking, just looks funny.