I would have done an excellent job in fact I used to do it in my other house that if I removed everything absolutely everything from the space to wallpaper and paint, protect my floor and then get to work without throwing dust or make a mess like the one you are showing us.
Please, who would think of doing a wallpapering and printing job without removing all the belongings from the space!!!!
No wonder the color turned purple and blackened like an anal hemorrhoid.
Exactly. If you are going to do a job you do it right. None of this half hearted nonsense! :0)