Crossposted from my comment at Metacool :

Close! Black LOWERS the Earth’s albedo (reflectivity). Good thoughts, even so. Black cars also consume more energy via air conditioning, and need to be washed more often.

Even more important to the air conditioning problem is the amount of heat accepted an stored by the materials in the cabin that make up the seats, dashboard, steering wheel, etc. We have a 2003 Mini Cooper, light blue with the white roof, but the nearly-black plastic and leather interior soaks up a lot of heat during the day and back-radiates it into the air and my body during the drive home. It takes a lot of energy to cool those surfaces and the air that they are busy heating.