This is just my experience, but Tipper, my big black ol' guy is very sensitive to heat/sunshine. He overheats in summertime much faster than my other dogs ever have. I've also had two black females who didn't seem as sensitive as Tipper, but still more sensitive than my brindles and fawn.
By the same token, in winter, the black fur soaks up the sun and keeps them warm longer too. Tipper can go without a sweater in lower temps than my girls.