Colorado Cosmetology Written Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

Colors that contain aniline derivative tints, which are synthetic dyes, can potentially cause adverse reactions on the skin. In order to prevent this, a match test is required before application, where a small sample is applied and checked for adverse reactions. This is different from a patch test, which is used to test for compatibility of products, rather than specifically aniline derivative tints. A shade test is not necessary as the color will not change, and a tone test also does not accurately measure for potential reactions. Therefore, the correct answer is A, a match test.