That was a crazy sleepover I had as a kid and we had carpet on the stairs. Ouch.
When I take my children up those 'one day' stairs to tuck them in and read them stories, I would be so happy as each foot landed on one of these.
Those stairs can be painstakingly stenciled or wallpapered beautifully. They can also simply be sanded and given a lick of bright paint. Rainbow colours. Its for the kids you know.