Delaware Cosmetology and Barbering Practice Exam

A developer, often referred to as an oxidizing agent, is primarily used in hair coloring processes to activate the dye. It contains hydrogen peroxide, which plays a crucial role in facilitating the penetration of color into the hair shaft. When mixed with hair dye, the developer opens the cuticle layer of the hair, allowing the color molecules to enter and alter the natural pigment of the hair. This process not only helps in achieving the desired color but also ensures that the color lasts longer and appears more vibrant.

While lightening the hair involves the use of a developer, its primary function in coloring is activation and penetration of the dye. Conditioning and adding shine are secondary effects that may occur due to the hair products used but are not the fundamental purpose of a developer. Hence, the role it plays in hair dyeing makes the choice about using it to activate the dye and facilitate color penetration the correct one.