Satin's Cover Grey developer has wetting agents which make your desired color cling to the hair shaft allowing for better color penetration. Cover Grey has mordents which allow the color to adhere to the internal workings of the hair much more effectively. Mix up with Satin color into a rich creamy-gel consistency easy spread-ability and a stay put application. The silicone base in the Satin developers provide a color protecting barrier on the hair fiber resulting in a much longer retention of color. The end result is silky shiny long lasting hair color.*Packaging may vary*