What is the primary goal of performing a patch test before a coloring service?

The primary goal of performing a patch test before a coloring service is to determine possible allergic reactions. This test is crucial because it helps identify any sensitivity or allergies that a client might have to the chemicals in the hair dye. Hair color products contain various ingredients that can cause allergic reactions in some individuals, leading to redness, itching, or inflammation of the skin, particularly in sensitive areas such as the scalp. By conducting a patch test at least 48 hours prior to the service, cosmetologists ensure the safety and comfort of their clients, reducing the risk of adverse reactions during the coloring process.

The other aspects listed, such as checking for hair temperature, assessing color preferences, or evaluating moisture levels, while important in their own right, do not directly relate to the immediate health concern of potential allergic responses to hair dye. These factors are more about the application and effectiveness of the hair color service rather than addressing the client's safety and well-being regarding allergic reactions.