White vehicles everywhere, especially in the south (although when we lived in Orlando, I was flabbergasted at the number of black vehicles there!). And of course, the lion's share of light- to medium-duty commercial vehicles are white as well.
Coolest color to be sure, but nice light shades of green, blue, and gold (or champagne) are also cooler choices, and at least give the vehicle a little personality. Two-tones (white with a contrasting color) also tend to make your vehicle look a little less like everyone else's.
To each his own!