Changing Hair Color

If ever there was a mark of our desire to change the way other people see us, changing hair color has to be it! For example, for thousands of years Indian ladies have put red highlights into their dark hair using pure henna, a semi­permanent dye prepared from the Egyptian privet (Lawsonia inermis), a flowering shrub that grows in their country.

We particularly value the color of our hair. We may perhaps quickly pull out the first gray hairs that we notice - but we all know that will not be the end of the matter. Once the hair follicle has stopped producing pigment cells, it is highly unlikely to start again. The 'new' hair will be gray too.

Hair color is due to the present of melanin pigments in the cortex of the hair shaft. As we have seen there are two kinds of pigment, eumelanin and phaeomelanin. The cuticle is colorless and translucent: it looks like a polythene sheath. The color we see is due to a combination of light that has passed through the colored cortex and light that is reflected by the smooth cuticle.If there is no pigment in the cortex, the hair looks white.

The color of hair can be changed in only three ways:

• it can be made lighter, either wholly or in part
• it can be made darker, either wholly or in part
• it can be changed to an entirely different shade, either wholly or in part.

A clever stylist who understands color chemistry and the color circle can produce excellent tinting in keeping with the client's expectations: this, together with regular styling, produces a satisfied client

This lady has always used natural henna to color her hair

The color circle

You probably learnt at school that sunlight is made up of light of many different colors. You may perhaps have seen those colors in the glittering flashes of light that sparkle in a diamond. A more everyday sighting is in a rainbow. In a bright rainbow you can clearly make out the separate colors arranged in order, with red on the outside and violet on the inside of the arc. This array of colors is called the spectrum. In the spectrum of sunlight, colors that are similar to each other - red and orange, for example - are seen side by side, and blend together.

Color scientists have a special way of viewing the spectrum. The colors are arranged in a circle, in the way shown here. In this color circle similar colors are still placed side by side, but they are separated from each other . 

There are three basic or primary colors: red, yellow and blue. These are spaced equally around the color circle. In between them are the colors made by combining the primary colors together in pairs: these are called combination colors. Orange is produced by combining red and yellow, green by combining yellow and blue, and violet by combining blue and red.

Yellow, orange and red are often seen as 'warm' colors, and violet, blue and green as 'cold' colors.

All the combination colors come in different shades: for instance, you get a reddish orange if there is more red than yellow in the mixture, and yellowish orange if there is more yellow than red. The exact shade depends on the proportions of the colors in the mixture.

In the color circle, each of the primary colors lies opposite a combination color: red lies opposite green, orange lies opposite blue, purple lies opposite yellow. These pairs of 'opposite' colors are called complementary colors. If you mix red and green, you get neither red nor green but a greyish color. The same applies with the other complementary pairs. They cancel each other out when they are mixed.

It can be extremely useful to understand this effect when you are coloring hair. Suppose a client's hair has an orange tinge after bleaching: coloring lightly with the complementary color blue will cancel out the unwanted orange. Similarly if hair has an unpleasantly yellowish look, tinting with the complementary color violet may provide a solution.

Some interesting results are seen when more than two colors are mixed. A mixture of red and violet looks brown. Suppose we add a little yellow: the yellow and violet produce grey, and the result is a softer, more mousy brown. Add a little red instead, and you may get a chestnut color. Mixing red, yellow and purple together will give black, or at least a very dark gray.

In the practical world, the six colors of the spectrum are not enough to meet all our needs in hair coloring. But hair color manufacturers can get any color a client might choose by the careful mixing of these six, plus black and white, in various proportions.