Why does hair color hold such fascination? Hair color can be that magic wand that instantly transforms dull mousy locks into glorious golden lights that shimmer and shine. It can also instantly erase years of age by covering gray, adding depth to fading colors and cranking up overall shine. Depending on what you are trying to accomplish, hair-coloring products will almost always require the use of some form of chemical agents. Whether to use a permanent or semi-permanent color depends on several factors. "If more than 50 percent of your hair is gray, or if you want to lighten your hair, you have to use a permanent color with peroxide.

For a truly natural hair dye option, consider henna, which is made from the powdered leaves of a desert shrub called Lawsonia. Henna has been used for thousands of years to color hair and skin. (Cleopatra was a famed proponent.) Although it seems to pose no health risks, some sensitive people might still experience allergies when using it. Coloring agents for hair are of four main types: temporary hair color, natural colorings, semi-permanent dyes and permanent dyes.

Temporary hair color

The dyes used as temporary hair coloring agents were originally developed for use in textile industry. They are acidic dyes that are deposited on the outside of the hair, so they do not penetrate the hair shaft. They affect the way in which the cuticle reflects light, and they tend to make the hair look flat. They are easily shampooed off the hair, so they last through only a few washes. They are available as rinses, gels, mousses and sprays. Natural hair dyes do provide rich, long-lasting color with fewer chemicals. "But to get long-lasting color, you need chemicals, and some products have more than others.