Tennessee Cosmetology Practice Exam 2025 - Free Cosmetology Practice Questions and Study Guide

The primary purpose of using a toner in hair coloring is to neutralize unwanted tones in the hair. After the initial color process, especially when lightening hair, some undesired undertones can emerge, such as brassy or yellow hues. Toners are formulated to adjust the hair's color by adding specific pigments that counteract these unwanted tones. For example, a violet toner can help neutralize yellow tones, while a blue toner can combat orange tones. This process enhances the overall hair color, giving it a more balanced and refined appearance, which is crucial for achieving the desired final look.

Other options mention features like lightening or deepening hair color, which are related to the primary coloring process rather than the adjustive role of a toner. Additionally, providing shine and luster is more a characteristic of certain finishing products rather than the primary function of toners in color correction.