Just For Men shampoo-in hair color natural real black - kit is specifically formulated to colour mens hair. Just for men haircolour won t change your natural colour. It actually targets grey and blends in several close but different shades that match the rest of your hair. It s been improved with a unique complex of Vitamin E protein chamomile and aloe for thicker healthier-looking hair that s easier to control. One application or Just for Men lasts up to 6 weeks it wont wash out wont fade out no matter how often you shampoo. Lasts until the grey grows back. If you are not sure which colour to choose we advice that you choose a slighty lighter colour rather than a slightly darker colour.