Buy Youthair Hair Color Gray Coverage – Youthair Creme for Men and Women 16.0 oz. How-to-Use: Massage a small amount into hair and scalp. Apply daily until desired color is obtained and then as often as needed to maintain color. Exposing hair to sunlight will increase the darkening affect. Do not shampoo for at least 3 hours after application. Wash hands to avoid skin discoloration. Do not dilute with other styling products.