Rock the Colorado Cosmetology Written Exam 2026 – Beautify Your Career Today!

Gradual color is the only option that specifically mentions a grayish build-up on the hair, indicating a gradual change in hair color that can result in a grayish tint. While highlighting, permanent color, and temporary color are all commonly used to change hair color, they are not known to cause a grayish build-up on the hair. Therefore, they are incorrect options.