As has been mentioned previously their is no "correct" colour for AV15+. ABC and SBS use the red colour for their equivalent "MAV" classification.
Despite that, its probably just some sort of colouring error (which is probably bought on by a lack of real standard) whenever they're made up.
I think only SBS has an MAV classification. The ABC doesn't have an equivilant rating.
MAV is stupid imo.