A customer has a question (which is actually the title) and I hope we can get some opinions on it, thanks
I’m not sure what the color of rock has to do with it
I think what the customer is asking, is whether white colored rock might reflect light better than a say black rocks. Therefore keeping evaporation down.
Perlite or vermiculite will aid in aeration and moisture control in soil. Add some to dense soil for better drainage.