Using Arctic Fox's Periwinkle hair colour is easy. First, make sure your hair is pre - lightened to a level that can show the colour well, preferably platinum. Always do a patch and strand test at least 24 hours before full application to check for any allergic reactions. When you're ready, put on gloves and apply the hair colour evenly to dry hair. You can leave it on for the recommended time, usually around 20 - 30 minutes, but you can adjust it according to how intense you want the colour. After that, rinse your hair thoroughly until the water runs clear. To maintain the colour, use a sulfate - free shampoo and conditioner. Also, try to avoid excessive sun exposure as it can fade the colour. If you want to create different shades, you can mix a bit of Sterling to get a light denim blue or add a little Poseidon for a more pigmented look.