For more than 15 years, American Crew has been the salon brand that men trust. American Crew gray blending system gives you the ability to create the natural color in just five minutes. What else you need to know:  Lasts 4-6 weeks (24 shampoos) Easy to use and apply Fades to-tone with no brassiness 5 minute application with natural results No line of demarcation Choose a shade of American Crew Precision Blend (Light, Medium Ash, Medium Natural and Dark) that matches your natural hair color using your Precision Blend Swatch Guide. Then, mix the color with American Crew Developer 15 Volume 4.5% in a 1:1 ratio in a color bowl. In general, about 20 ml will be needed to complete the service on a client with long hair. You should perform a quick allergy test according to the warnings on the color product.  Each of the techniques can be used with light, medium or heavy product application to provide 25%, 50%, 75% or 100% gray blending. For a natural look, allow gray to peek out at key areas such as sideburns and temples. Perform each technique efficiently, trying to keep the application time under four minutes.