What are aniline derivatives commonly known as in the context of permanent haircolor?

Aniline derivatives are commonly referred to as dye precursors in the context of permanent haircolor because they are the primary building blocks that produce the final color. When applied to hair, these compounds undergo a chemical reaction, typically through a process of oxidation, resulting in the formation of larger, more complex dye molecules that provide permanent coloration. This ability to transform into larger pigments is essential for achieving vibrant, long-lasting results in hair coloring.

The other options do not accurately describe the role of aniline derivatives in permanent haircolor. Hair lighteners are typically used to lift or lighten the natural hair color but do not directly involve aniline derivatives. Pigment enhancers might suggest a role in intensifying existing colors, but they do not reflect the fundamental function of aniline derivatives. Color stabilizers would imply a role in maintaining the vibrancy of the color post-application, which is also different from the primary function of aniline derivatives as the reactive components that create the color in the first place.