When I was growing up on the east coast, there was this silly rule about wearing white in the summer. Except it really wasn't so silly, because lighter colors are shown to help reflect hit and keep you cooler when it's ridiculously hot outside. Think about how blazing hot the asphalt in parking lots can be. How often do you find similarly dark colors around a swimming pool?
Now theories around color are being applied more seriously to rooftops. Most roofs are, quite frankly, dark. Gray, slate, dark green, terracotta. Some materials absorb or reflect heat better than others. Now, a new survey suggests that developers need to be less color blind about there choices. A new Department of Energy study shows that cities could take the equipment of 300 million cars off the road by using white roofs.