1. The first step:
You will need white, or nearly white hair. Get blue packets. I used L’Oreal Quick Blue. Depending on the length of your hair you may need one, two or even three packets. Mix it with 30 volume developer. SalonCare brand is what worked for me. Mix the amounts evenly in a bowl, put on gloves, and then put the mixture in your hair. How long you leave it on depends on how light your hair already is. For dark hair, 45 minutes to an hour is what I did. You may need to bleach your hair like this more than once. Wait a week in between each bleaching, and deep condition at least once in between bleachings as well.
2. The Second Step:
At this point, your hair should be pretty light blonde. If not, continue the bleaching. Buy Shimmer Lights shampoo & conditioner, which is supposed to bring your hair to a silvery color/enhance what you already have. The bottle says to leave it on for 3 minutes (if I remember properly) but I would leave the shampoo on for 10, and the conditioner for 20. I didn’t use this product everyday, as it is very drying. But every other day is perfectly fine.
3. The Final Step
Gentian Violet is key, and is what makes your hair have what looks like purple/blue chunks in it. Gentian Violet is available at many pharmacies, but I had to to order it and wait a week, because it was out of stock at the one I go to. What you will do is mix it with your conditioner. The conditioner has to be white, and I used Dove Moisturizing conditioner for myself. Make sure the Gentian Violet is pretty well mixed in, and put on after shampooing. Do this for about 3 days in a row, and you should finally have that mermaid hair you’ve always wanted. :)