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.


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

You can buy the Greg May Ultra Violet at the salon or at the online store! http://www.gregmayproducts.com !
