Something a little less… permanent perhaps?

Something a little less… permanent perhaps?

I absolutely loathe white walls in a home. One, everybody else has got them, and two, it's very boring. I'm thinking of going with red and slate with non-metallic silver accents, but my problem is I don't want to actually paint the walls, mainly because I'm renting, and I don't want all the hassle of obtaining permission, painting the walls, and then having to repaint them when we move out, which hopefully won't be for a while. I kinda like it here. I got one idea last night whilst watching Changing Rooms, but I'm not sure if it's practical, or if there's a better way. I'm considering papier mache'ing coloured paper up to the walls for a kind of art deco approach to wallpaper, but that goes back to the whole "permanent" thing, as I'm not entirely sure how easy it would be to remove. Has anybody done this, or know of other non-permanent, not super crazy expensive solutions to white walls? As of right now, I only want to do my front room and kitchen, but if I like the results, I may wind up doing the entire flat. Thanks :)
another i.d please..

another i.d please..

Heligan gardens, Cornwall

Heligan gardens, Cornwall

Neato tree bark

Neato tree bark

My bedroom ’09

My bedroom ’09

Full garden

Full garden

Are they lilies?

Are they lilies?