What is the term for color that dyes the fiber directly without any oxidation?

The term for color that dyes the fiber directly without any oxidation is "direct dye." These dyes work by penetrating the hair shaft and binding directly to the fiber, allowing for immediate coloration without the need for a chemical reaction. This makes them particularly effective for providing vibrant colors and is often used in semi-permanent hair color formulations.

Direct dyes do not require an oxidative process to achieve their color effect, differentiating them from oxidative dyes, which need a developer to activate the coloring agents and change them chemically within the hair. This characteristic allows direct dyes to typically deposit color quickly and can result in a more vivid appearance on the hair, although they may wash out more quickly compared to more permanent options.

In contrast, dye intermediates are the precursor compounds that require oxidation to form the final color and are typically used in permanent hair color formulations. Drabbers are used to counteract unwanted warm tones in hair, such as brassiness, while fillers are applied to even out porosity and provide a base for subsequent color applications. Understanding these distinctions is crucial for effective hair coloring techniques and achieving desired results.