The concept seems right, black would absorb more heat thus making the tank hotter but have not tested the theory. If heat is an issue throw on a chiller.
I prefer the oolitic white aragonite. I got a few bags of the Southdown aragonite playsand I have been lugging around for the last 8 years. The wife thinks I am crazy. I treat it like gold even though it was only $5 a bag. Not sure how much a 50# bag of aragonite sand goes for now.
When you decide with black or white then get a live sand kit. Make sure it is not bioactive sand but true live sand with macrolife (pods, worms, stars, etc).