Which type of hair color lasts the longest?

The longevity of hair color largely depends on the type of color product used. Permanent hair color is formulated to provide long-lasting results by penetrating the hair shaft and allowing the dye to chemically alter the natural pigments. This process involves using a developer, which opens the hair cuticle and allows the color to bond effectively, leading to vibrant, lasting results that grow out rather than wash out.

In contrast, temporary hair colors coat the hair surface and can be easily washed away with shampoo, typically lasting only a few washes. Semi-permanent colors do penetrate the hair but do not alter the hair structure as significantly as permanent color, which means they typically fade after several weeks. Highlights, while they can offer a long-lasting change depending on the technique, do not encompass the same type of all-over color as permanent dye and are often lighter or blended with a natural shade.

Given these factors, permanent hair color stands out as the choice that will provide the longest-lasting results.