Don't worry, Banksy is always waiting to strike just around the corner to spice up the place. Although then there is the risk of someone removing the wall and selling it. Also I noticed his latest thing got immediately scribbled over..
Honestly though the bright colours are mostly on the highly visible houses on hillsides, as soon as you get into the thick of the houses, even up in fancy Clifton it all turns a lot less colourful for 99%. Not that there's anything wrong with that, I think people just like having their house as part of the view, and contribute their little bit, just so they can say "I'm the pink one on the end" - I would :D
Honestly though the bright colours are mostly on the highly visible houses on hillsides, as soon as you get into the thick of the houses, even up in fancy Clifton it all turns a lot less colourful for 99%. Not that there's anything wrong with that, I think people just like having their house as part of the view, and contribute their little bit, just so they can say "I'm the pink one on the end" - I would :D