What is the primary purpose of using hydrogen peroxide in hair color?

The primary purpose of using hydrogen peroxide in hair color formulations is to lighten the natural pigment of the hair. When hydrogen peroxide is applied, it acts as a bleaching agent that opens the hair cuticle and allows color molecules to penetrate deep into the hair shaft. This process helps to lift the existing pigment from the hair, whether that is to achieve a lighter shade or to prepare the hair for subsequent color application.

In the context of hair coloring, the ability of hydrogen peroxide to oxidize and break down the melanin (the natural pigment responsible for hair color) is crucial. Different concentrations of hydrogen peroxide can be used depending on the desired level of lift; for instance, a higher concentration may be needed for a more dramatic change in color.

While enhancing shine, disinfecting tools, and strengthening hair follicles can be important aspects of overall hair care, they are not the primary functions of hydrogen peroxide in the hair coloring process. Its main role is specifically related to the lightening of the hair's natural pigment, thus making color application more effective.