Easy Comb-In Hair Colour. Easy: Comb-in applicator allows for controlled application to where the grey is: certain areas or all over. Shuts Off: Shuts itself off so it can't go too dark. Always looks natural. No Mix, No Mess: Just comb-in, shampoo out. Takes only 10 minutes. Gentle: No peroxide. No ammonia. Leaves hair feeling soft & manageable. Long lasting: Permanent grey coverage. Lasts up to 6 weeks until the grey grows back.