What reaction occurs when permanent hair color is applied?

The application of permanent hair color triggers an oxidation reaction. This process involves the interaction between the hair color formula, which includes a developer (usually containing hydrogen peroxide), and the hair's natural pigment. During oxidation, the developer acts to lift the cuticle of the hair, allowing color molecules to enter the hair shaft. Once inside, the small color molecules undergo a chemical change, becoming larger and more complex molecules that can't easily escape, thus providing long-lasting color.

This oxidation process not only deposits color but also lightens the natural pigment of the hair, which is why permanent hair color can effectively achieve a range of shades and tones. The use of a developing agent that facilitates this oxidation reaction is what distinguishes permanent hair color from other types of hair dyes. Understanding this chemical process is essential for effectively managing hair coloring procedures and achieving desired results in clients.