What is a primary characteristic of permanent hair color?

A primary characteristic of permanent hair color is that it does not wash out and changes the natural pigment of the hair. This type of hair color contains a chemical reaction that alters the hair's structure, allowing it to penetrate the hair shaft and deposit color that is long-lasting. Unlike semi-permanent or temporary colors, which can gradually fade with washing, permanent colors provide a more enduring change, often requiring regrowth or color touch-ups as the natural hair grows out.

While options relating to semi-permanent characteristics or easy wash-out might describe other types of hair coloring products, they do not apply to permanent hair color. Additionally, while some hair colors may offer conditioning benefits, the defining trait of permanent hair color is its lasting impact on hair pigment, confirming why it is recognized for making substantial and enduring changes to hair color.