What is the main characteristic of permanent hair color?

The main characteristic of permanent hair color is that it causes lifting of the natural color. Permanent hair color contains a combination of ammonia and peroxide, which allows it to penetrate the hair shaft. This process involves lifting the natural pigment in the hair, which enables the new color to be deposited at a deeper level. As a result, the change in hair color is long-lasting and does not wash out like temporary hair colors, which only coat the outer layer of the hair. This lifting process is what differentiates permanent color from semi-permanent and temporary options as it can lighten the natural shade and deposit the desired color effectively, creating a lasting effect. Additionally, because of this lifting capability, permanent hair color is often used for gray coverage and when a significant change in color is desired.