Wyoming State Board Cosmetology Practice Exam 2025 - Free Cosmetology Exam Questions and Study Guide

Permanent hair color requires the use of a developer because it contains ammonia or a similar alkaline agent that opens the hair cuticle, allowing the color to penetrate deeply into the hair shaft. The developer, which is typically hydrogen peroxide, activates the color molecules and facilitates the lifting process, necessary for achieving a long-lasting and more vibrant color change. This connection between the developer and the permanent color formulation ensures that the dye stays within the hair structure, providing lasting results.

In contrast, temporary hair color does not require developer since it coats the outside of the hair and washes out after one or two shampoos. Semi-permanent hair color also does not need a developer; it is designed to fade over time and typically lasts longer than temporary color but does not achieve the same depth of color. Demipermanent hair color lies between semi-permanent and permanent color; it can last longer than semi-permanent without the intense penetration and commitment of a permanent color, and it is often used with a lower-volume developer, but it still does not require the same amount needed for permanent hair color.