Fast and easy Shampoo-In formula for a natural gray-free look. Just For Men Shampoo-in hair color covers your grays completely, permanenty and effectively. It targets only the gray hair and preserves subtle variations of your natural hair color. This easy to apply non-drip hair color only takes five minutes to color every single gray hair, and lasts until the gray grows back. It leaves your hair looking healthier and thicker after every application.