I'm flying to Garden City, NY today to see a Pearl Model S in person. I, too, have narrowed the color choices down to black, white and silver. I've heard that the Pearl is quite stunning. I do find that a white Model S looks more sporty with a black roof. The pano roof has basically the same effect.
I've seen the color samples in the Natick MA store. Most of the colors are disappointing, given how much thought went into the design of the body. The gray, best described as a gun-metal gray, is too cool (blue) for my taste. I wish there were more subtle metallic choices available.