To use Crazy Color Sapphire, first do a strand and sensitivity test. Then shampoo your hair with a pH neutral shampoo and don't use conditioner. Pat your hair dry with a towel and apply the dye directly while your hair is still damp. Spread it evenly and wear gloves. Leave it on for 15 to 30 minutes, then rinse thoroughly until the water runs clear. Remember, this is a semi - permanent color, so it will fade with each wash. Try to use a sulfate - free or color - friendly shampoo and wash your hair as little as possible. After shampooing, rinse your hair with cold water to seal in the color. Also, avoid too much direct sunlight and swimming as they can strip the color from your hair. If you have any redness or itching after using the product, stop using it right away.