We used to do it all the time at the counter when I worked at Dominos back in the day. If it was a ginger person we would point and say the Ginge in the corner, if it was a black person we would say the darkie or the black in the corner, and if it was a blonde person we would say the blondy in the corner. You have use the first recognisable feature you could see about the person, saves time and effort.
People used to complain about it but I cant see anything wrong.
Edit: Nearly forgot if they were fat, we would say the fatty in the corner, only problem is half the place would turn round.