Hair Color 101
I’ll bet you didn’t know that the first safe commerical hair color was created in 1909 by a French chemist. The chemical used at that time was paraphenylenediamine. I know, try saying that fast three times!
Today, coloring hair is so popular that over 75% of women color their hair and a growing number of men are following suit. How does the hair color process work? It is the result of a series of chemical reactions between the molecules in hair, pigments as well as peroxide and ammonia.
Your hair is mainly keratin, the same protein found in skin and fingernails. The natural color of hair depends on the ration and quantities of two other proteins, eumelanin and phaeomelanin. Eumelanin is responsible for brown to black hair shades while phaeomelianin is responsible for golden blond, ginger and red colors. The absence of either type of melanin produces white and gray hair.
Temporary or semi-permanent hair colors may deposit acidic dyes onto the outside of the hair shaft or may consist of small pigment molecules that can slip inside the hair shaft, using a small amount of peroxide or no peroxide at all. In some cases, a collection of several colorant molecules enter the hair to form a larger complex inside the hair shaft. Shampooing will eventually dislodge the temporary hair color. Temporary or semi-permanent colors don’t contain ammonia, meaning the hair shaft isn’t opened up during processing and the hair’s natural color is retained once the product washes out.
Bleach is used to lighten hair. Bleach reacts with the melanin in the hair, removing the color in an irreversible chemical reaction. The bleach oxidizes the melanin molecule. The melanin is still present, but the oxidized molecule is colorless. However, bleached hair tends to have a pale yellow tint. The yellow color is the natural color of keratin, the structural protein in the hair. Bleach reacts more readily with the dark eumelanin pigment than with the phaeomelanin, so- some gold or red residual color may remain after lightening. Hydrogen peroxide is one of the most common lightening agents. The peroxide is used in an alkaline solution, which opens the hair shaft to allow the peroxide to react with the melanin.
The outer layer of the hiar shaft, it’s cuticle, must be opened before permanent color can be deposited into the hair. Once the cutilcle is opened, the dye reacts with the inner portion of the hair, the cortex, to deposit or remove the color. Most permanent hair colors use a two -step process, occuring simultaneously, which first removes the origional color of the hair and then deposits a new color. It’s basically the same process as lightening, except a colorant is then bonded within the hair shaft. Ammonia is the alkaline chemical that opens the cuticle and allows the hair color to penetrate the cortex of the hair. It also acts as a catalyst when the permanent hair color comes together with the peroxide. Peroxide is used as the developer or oxidizing agent. The developer removes the pre-existing color. Peroxide breaks chemical bonds in hair, releasing sulfur, which accounst for the characteristic odor of haircolor. As the melanin is de-colorized, a new permanent color is bonded to the hair cortex. There may be various types of alcohols and conditioners present in hair color.
Relevant Tags:hair bleach, permanent hair color, semi permanent hair color, temporary hair color


















