Paint colors can have a huge impact on the energy efficiency of our homes. It's more and more common these days to use white or reflective roof coatings to keep buildings cooler in summer, since a black tar roof will absorb heat rather than reflect it outward. The same basic principle goes for exterior painting: Lighter, more reflective colors will help buildings stay a little cooler during those long sunlit summer days. But even interior color choices can affect energy efficiency. The al...