If you want to do black on top, I vote for only the pillars and roof be black. My biggest problem with that paint scheme though is the paint lines on the C-pillar/rear quarter. There's no really clean body line to follow there to give you a clean transition between the black and whatever other color.
I say go for it though. I always thought a car would look cool white or black with a colored roof, like a dark purple or red. No idea how it would look in real life though, probably a job for a photoshop guru.