You clean your car often? If you do, giving the wheels a good clean isn't gonna take much time. But if you leave washing your car for couple weeks and let the brake dust and everything settle then prob isn't worth it.
Have to admit when I had the gray one's hardly cleaned the wheels and it was fantastic not having to do it.
Think black and a unlowered car would look alright, but white with the gap the almera's have it would look stupid. It would make the car look even higher imo.