Grunge.

This is one of the rooms in the house that the "lads" are renovating. And I must stress that it wasn't actually anywhere nearly as bad as it looks.
Someone had actually painted the word "HELLO" on the wall, but then the "O" had been covered over by new plaster...
A few "games" in photoshop did the rest - and turned what will be quite a pleasant room, when it's finished, into a grotty squat.
Sorry Lads!!