Final answer:
A temporary color rinse applied to hair will gradually wash out over time with shampooing and does not permanently alter the hair's structure. It lasts until the next shampoo and offers a way to experiment with colors non-committally.
Step-by-step explanation:
If a temporary color rinse is applied to normal hair, it will gradually fade and wash out over time. Temporary hair color typically lasts until the next shampoo, as it simply coats the hair shaft without penetrating into the hair's cortex. Thus, temporary color does not alter the hair's natural pigment or structure, unlike permanent hair color, which chemically alters the hair until it is cut away. Temporary colors and rinses offer a non-committal way to experiment with hair shades since they do not offer the same longevity or change in hair structure as permanent dyes.
In the context of semi-permanent hair color, it will wash out after about four to six weeks. It is less damaging compared to permanent dyes and often results in a more natural look because the final color can be influenced by the hair's original color and porosity. Contrary to semi-permanent dyes, permanent hair coloring involves a chemical change, removing the natural color and infusing synthetic pigments, which will fade over time but the change in hair structure will remain until the hair is cut.