Before we answer those questions, we'll need a little background!
DOMINANT PIGMENT
also known as contributing pigment, underlying pigment, or residual pigment, is a key element in determining the color of your hair, and comes into play when lightening your hair either chemically or naturally. Let's take for example someone with dark, black asian hair who wants to be a blonde. When you lighten their hair with lightener (bleach! usually hydrogen peroxide), it doesn't go straight from black to blonde. Hydrogen peroxide (H2O2), breaks up and oxygen (O2) molecules attack the melanin molecules in your hair responsible for your hair color. There are two types of melanins in your hair, eumelanin and pheomelanin. Eumelanin is responsible for darker brown and black tones while pheomelanin provides red, yellow, and ginger tones. Anyways, so when you have hydrogren peroxide in your hair it attacks the bigger eumalenin molecules first; they're easier to separate. These molecules break down into oxymelanin, which is similar in tone to phemelanin. What this all means is that your hair lightens progressively, as eumelanin is broken down first then pheomelanin. As the ratio of eumelanin decreases, pheomelanin becomes more apparent and the tone of your hair goes through stages: black -> brown -> red -> red-orange -> gold -> yellow. This can also happen naturally, hair expose to the sun becomes oxidized, and brown hair turns reddish while blonde or white hair turns goldish.
This oxidation, whether natural or chemical, is where purple shampoo comes into play. When your hair is lightened in the salon, it's usually followed with a toner to create a suitable haircolor; no one likes leaving the salon with orangy hair! The toner chosen is highly dependent on the level which the hair is lightened to. Each level of lightness has a different underlying pigment to deal with, and it is toned with a color that will neutralize that. Basically if you looked a color wheel, find the color of the underlying pigment and go directly across and that's the color base to neutralize it with. So a green base will neutralize a red dominant pigment, a blue will neutralize an orange/gold shade, and what will neutralize yellow? PURPLE! The chart sums up everything we've talked about here, showing each level of lightness and it's dominant/neutralizing pigment =)
So purple shampoo helps blondes and nordic blondes (grey/white!) deal with the natural oxidation that comes along with having very light hair, neutralizing brassy/yellow tones in the hair. I went blonde a few months ago and I love being a blonde but my hair goes yellow fast, it loves warm
tones. Usually I don't really mind it so much but I decided to give my boss's purple shampoos a try and see what they'd do to my hair. I use it all the time in the time in the salon and it's always had great results so I had high hopes, and it didn't disappoint. You can see in the picture here what my hair looked like before and after! I used the Greg May Ultra Violet shampoo and conditioner, which deposits purple color pigment into your hair as you wash/condition it! One or two washes with the shampoo, and I left the conditioner in for a few minutes in the shower (you can even use it under heat for even better results), and it toned down all the brassiness in my hair! You can see it's a lot less yellow and more of a cool, wheaty color; more blonde! It's awesome, I love it. Plus, the shampoo is actually a really pretty purple color -> +1billion cool points.You can buy the Greg May Ultra Violet at the salon or at the online store! http://www.gregmayproducts.com !



















