In just a few minutes, you can look and feel five years younger. American Crew grey blending doesn't require a special visit to the salon, with foils and long waits at the shampoo bowl. Most of the techniques can be performed in less than four minutes. And the colour needs just five minutes to process on the hair.Benefits Lasts 4-6 weeks .Easy to use and apply Fades to-tone with no brassiness. 5 minute application with natural results. No line of demarcation, Tone on Tone Works in 5 minutes.