I REALLY DO want your opinion

I've never had these kinds of heaters before. I guess they are radiators, but seem different than ones that I have seen before (generally, I've only seen radiators in home improvement shows from the east coast.) Anyway, instead of a central place to control your heat, there is a radiator (or two or three) in each room. That isn't my problem, though. My question is how should I paint around the radiator. In our bedroom, the radiators are small and kind of cut into the wall, so I just left the small area around it white. (By the way, the walls are yellow, they look kind of weird in this picture.)Since the radiator is on this side wall in the guest room, I think I might be able to get away with leaving this wall white. (On a side note, there is this odd cut out area in the guest room. I'm sure it is from pipes or something. I think it would be perfect for a time out seat, but it's in the wrong room.)

However, in the living room, I'm pretty sure that it will look weird if I leave that wall white. So, what do you think, can I get by with leaving any of these walls white? If I paint those walls, should I try to paint around the radiator? Or do I need to paint the whole wall? I think I know that answer. Those radiators just are not close enough to the wall to avoid painting. If we owned this house, I would absolutely paint those walls behind the radiator, but I am (probably) going to have to repaint all of these walls in one to three years. Ok, tell me what you think.