There's been colour on these walls down the side of Clifton Bingo for as long as I can remember. Every now and then, it changes. It's just been repainted recently.
I don't know if the same person repaints this each time, or if it's someone different. I don't know if they were asked to do it, or just came along and did it. The fact that it's all a bit mysterious and unexplained makes it all that more interesting.

For photos of these walls in previous years, see York Walks /4: Wall art - part 2 and York Walks /3: Bits of Clifton.