The Science of Color: How Chemical Dyeing Processes Transform Hair Structure

This study explores the chemical processes involved in hair dyeing, focusing on oxidative and non-oxidative methods and their impact on hair structure. It highlights how hydrogen peroxide, alkalising agents, and dye precursors alter keratin, lift the cuticle, and increase porosity, while semi-permanent and direct dyes cause less structural damage. The paper also discusses new technologies like bond-repair additives and ammonia-free systems that aim to protect hair integrity while delivering effective color results, offering a biochemical basis for achieving a balance between aesthetic outcomes and hair health.