The human hair that is used in most hair systems has been processed in order to strip away the cuticle of the hair shaft and to change it's color. Since the hair (which is usually of Asian origin) starts out a very dark color, it must be dyed to the color necessary to make the hair system. The cuticle is removed in part to help the dark hair accept the dye and also to prevent the hair from tangling.

The dark hair is, in effect, bleached during processing, which makes the hair color a bright orange, and then the hair is dyed the correct color. Unfortunately, hair dye doesn't last forever, and when it begins to wear off, the reddish orange tint begins to show.

All human hair hair systems will eventually lighten in color. A good hair replacement company, however, will use a more complex process for treating the human hair, and they will use a more permanent dye. This way the human hair will last much longer.