Haircoloring products that change color gradually by progressive buildup and exposure to air contain which of the following?

• A. Metallic salts
• B. Organic dyes
• C. Plant-based pigments
• D. Salt crystals

Answer: (A)

Progressive color comes from metallic salts in the product. These metal compounds deposit in the hair and gradually change color as they oxidize with air and accumulate with repeated use. Each new application adds more metal, so the shade can deepen or shift over time, which is why this type of color is described as progressive buildup. Organic dyes and plant-based pigments color hair through chemical reactions during processing and don’t rely on air exposure to continue changing after you rinse, while salt crystals aren’t used as a colorant in hair coloring.