Before using this Crazy Color Peacock Blue hair dye, it's always a good idea to do a strand and sensitivity test. First, shampoo your hair with a pH - neutral shampoo and don't use conditioner. Then towel - dry your hair. While your hair is still damp, put on gloves and apply the dye evenly over your hair. Leave it on for 15 to 30 minutes, then rinse thoroughly until the water runs clear. To keep your color looking great, avoid using dandruff or harsh shampoos as they can strip the color quickly. Use a sulfate - free or color - friendly shampoo and wash your hair as little as possible. After shampooing, rinse with cold water to seal in the color. Also, stay out of too much direct sunlight and avoid swimming in chlorinated water as they can fade the color. And remember to patch - test any new product before continued use. If you experience redness or itching, stop using it.