This happened to a friend of mine. She and her husband rented a lovely old farmhouse. The owner had lived there with 3 teenagers, and allowed them to paint their rooms however they liked. Sound good? It should, except:
Boy's room 1 was painted all over - ceiling, walls, etc - in camo. Huge patterned camo.
Boy's room 2 was painted all over black, with a glow in the dark moon in one corner covering the ceiling and both walls
Girls room was painted day glo pink, with giant fluorescent flowers
It took her many, many, many buckets of primer to cover all that fluorescing.