Kentucky Cosmetology State Practice Exam 2025 - Free Cosmetology Practice Questions and Study Guide

Using a toner in hair coloring primarily serves the purpose of adjusting the tone of the hair color. After the initial hair coloring process, a toner can be applied to achieve a desired shade by neutralizing unwanted undertones—such as brassiness or dullness—that may have been produced during the dyeing process. Toners typically come in various shades, allowing for subtle color changes and enhancements, making the hair look more polished.

The other options focus on different aspects of hair care and hair coloring. Lightening the hair refers to the bleaching process, which is separate from toning. Adding shine usually involves finishing products or treatments rather than toning, and while certain toners may help enhance shine, their main role lies in adjusting color tone. Prolonging hair color longevity pertains more to aftercare products and techniques designed to maintain color integrity and vibrancy over time, distinct from the specific function of toners.