I've had both...
Black will drive you crazy trying to keep it clean, but looks AWESOME at night.
During the day, its a SOLAR heating system guaranteed to make you scream "Holy Sh!T"! when you climb into the car on a hot sunny day.
White stays cool, stays cleaner looking longer,(believe it or not...) and looks great day OR night.
It's your decision.
But it seems that white has more advantages.