We had once a really ugly wooden garden gate that was bothering me for quite a while. The landlord did not care. So I came up with the idea to put a left-over from a brick wallpaper we have produced for a client right onto the gate. Have a look how it was before and after:
I have done something something similar before with another left-over piece of wallpaper and it survived a couple of months - despite heavy rain and heavy sunshine, a dog and a teenager constantly going in and out. I was surprised myself, but the paste just dried after the whole thing got wet during the rain ... I have to see if I can find a photo of the first attempt.
Normally, I would recommend a special self-adhesive vinyl with an aggressive adhesive for this kind of purpose, this I see this only an temporary decoration anyway.