(cache) How Can Hair Color Change?

Bleaching

Sun-bleached hair
One effect of too much sun is a darker skin tone. By comparison, sun tends to lighten the color of our hair through a process called photobleaching. Because it is made up of dead cells, hair has less ability to absorb the sun's rays, so bleaching occurs to reflect sunlight back. The lighter in color something is, the more light it reflects. Blond or gray hair may start to lose enough pigment to become almost white in color where the sun hits it most often. Brown hair may become lighter brown or red where the sun highlights it.

You can use lemon juice or chamomile tea to increase the sun's bleaching. Often the tea or a dilute solution of lemon juice is sprayed onto the hair just before going out into the sun. There is a weak acid in both the juice and the tea that can start to bleach the hair.

Gray hair
As men and women age, their hair can start to turn gray. It can start graying as early as your 20s or as late as your 50s. In many people, body hair tends to gray before the hair on the head. The hair on the scalp can start graying anywhere, but it often starts near one of the edges of your scalp hair in the front or on the sides. The pigment cells in the roots of your hair no longer produce as much melanin, so that the hair can look transparent, gray, or white. As the hair follicles in the roots start to die with the onset of baldness, the hair around the edges of the bald spot or receding hairline can also lighten or turn gray.

Highlights using dye
Rinses produce a subtle change in hair color that is temporary. If you want to change the color of your hair to a shade lighter than your natural color, you may have to use a chemical bleach first. Hydrogen peroxide (a strong acid) and ammonia (a strong base) are used before dyeing hair, so it is important to not get them too close to the scalp, or they can burn and blister your skin. Once your hair is light enough, you can apply the dye or tint. You can choose a natural color or something more unusual such as blue, orange or fuchsia. Hair dyes often contain p-Phenylenediamine (PPD), which may cause allergic reactions, so some people prefer more natural red henna tints. "Black henna" may still have PPD in it.