Cloakroom decor ideas: crazy tiling?

The one room in my house that has never been decorated is the downstairs loo. After five years, the excitement of even having a such a room is wearing off – a bit – and the hastily executed white wash – damage limitation rather than re-decoration (it was lime green and acid yellow when I moved in) is now flaking off.

The "smallest room in the house" feels like a good place in which to be bold