Before coloring the entire hair, it is recommended to perform a color test on a hidden strand of hair. Choose the lightest strand or the area with the most gray hair. Use gloves. Mixing ratio: 1:3 (1 part powder + 3 parts boiling water, green or black tea, coffee, or sour milk product). Using a brush or hands, apply the color generously and as hot as possible to clean, dry hair. Start at the ends and work your way up. Wrap the hair in plastic film (plastic bag) and a towel to keep it warm and moist. Leave the color on for 25-90 minutes, depending on the desired color intensity. Rinse thoroughly and wash with shampoo. For best results, rinse with ZENZ Hair & Scalp Rinse no. 87 after washing the hair and before applying conditioner. Store in a cool, dry, and dark place.