Hair coloring, also known as hair dyeing, is the process of chemically modifying the hair’s color. The reasons for this are purely cosmetic: to augment the natural hair color or to hide grey or blond hair, to add a different shade considered to be more attractive or fashionable, or even to restore the original hair tone after it’s been whitened or dyed by hairdressing treatments. Hair coloring can be done in two primary methods – active ingredients such as iron salts or ammonia and natural dyes such as soy and dye solutions; or passive ingredients such as hydrogen peroxide or lemon juice. In addition to these options, there are now hair dyes that are applied using a brush.
The active ingredients in hair dye pigments or in natural hair colors are generally designed to react with natural hair pigmentation in the same way that chemicals in cosmetics and food do. They add to or diminish an individual’s natural hair tone. For example, madder root is used to lighten very dark or black hair. Similarly, cypress oil can lighten naturally dark brown or blond hairs. Lutein can make the hair darker. Orange peels and vitamin C is good for creating highlights.
Some hair dyes, particularly the acrylic type, are applied by pressing a pad of pigment on the scalp and massaging it in. Hair coloring products, including permanent ones, are available in both standard shades and novelty colors. Permanent hair colors are those that will not wash out or change over time. Popular colors include blues, reds, yellows, greens and tans.
Permanent hair coloring products consist of two key components – the irritant (carrots, corn, broccoli stems, eggs, soy beans and lemon seeds) and the coloring agent. The irritation is to be expected from the dyes, which are usually made of ammonia. The other ingredient, the coloring agent, is usually hydrogen peroxide. It oxidizes the nitrocellulose (cellular material that makes up the hair shaft) to form color. The more powerful the molecule that produces the color, the more permanently it will stay in place. However, even a tiny amount of residue can cause the color to fade over time.
The use of these colors was popularized by Marlisse Amore with her technique of non-drying permanent hair coloring. Amore’s technique included steaming the hair and then using a bleaching solution containing ammonia, she mixed it with lemon juice, rose water and glycerine to generate the color. Amore’s methods were popularized in the 1960s and became popularized by American singer and actress Ginger Clay. Other cosmetic designers also utilized the technique such as Jean Paul Gaultier, who introduced a line of “pink hair” that still remain popular today.
Although hair coloring can produce lighter and darker hair colors, they do not always lead to skin discoloration. When hair coloring is performed with dyes that contain melange (a natural hormone that helps control skin pigmentation), there is generally no skin discoloration. This is because the melange in the dye bonds with the enzyme in the hair shaft, stimulating its production. Hair coloring that contains melange does however have a negative impact on people with dark skin.