This article is a great introduction to the concept of dry shampoos. She reviews both using Bumble & Bumbles, which we carry at Pop, and the DIY method, cornstarch.
The Bumble & Bumble powders that we have always been a top seller, and one of the reasons people that are into dry shampoos love them is that they are colored, so they can help with hiding roots, as well as making that blow-out last a little longer.