The Color of Human Hair

The color of human hair was determined by the presence and ratio of two types of melanin: eumelanin and pheomelanin. The melanocortin-1-receptor (MC1R) gene played a crucial role in regulating melanin production, with mutations leading to red hair. Tyrosinase, an enzyme, controlled melanin production, with higher activity in red or blond hair and reduced activity in grey hair due to aging. Hair color could be assessed macroscopically or microscopically, and artificial coloring could be detected under a microscope. Hair was a common material in forensic science, with methods available to associate hair with individuals.