How are hair color products generally categorized?

Hair color products are generally categorized based on their chemical processes and interactions with the hair, which is why oxidative and nonoxidative classifications are significant. Oxidative hair color involves a chemical reaction where the dye molecules develop inside the hair shaft after an oxidant, typically hydrogen peroxide, is applied. This category includes permanent hair color, which changes the hair structure and lasts until the hair grows out or is cut.

Nonoxidative hair color, on the other hand, does not require a developer and often consists of temporary dyes that coat the hair rather than penetrating it. These typically wash out after a few shampoos. Understanding this categorization is essential for choosing the appropriate product for a desired outcome, ensuring that the stylist can achieve the right tone and longevity for their clients.

Categories such as natural and synthetic, permanent and semi-permanent, or liquid and powder do not provide the same depth of understanding regarding how the products function and interact with the hair, which is why oxidative and nonoxidative is the most relevant classification.