The pigment molecules in
temporary hair color are large and, therefore, do not penetrate the cuticle layer, allowing only
a coating action that may be removed by shampooing.
Acid dyes are used to coat on the surface of hair, since acid dyes have a low affinity to hair, thus can be removed after a shampoo.
Temporary hair color is available in various product forms including rinses, shampoos, gels, sprays, and others. This type of hair color is typically used to give brighter, more vibrant shades or colors such as orange or red, that may be difficult to achieve with semi-
permanent and permanent hair color. This phenomenon is due to the fact that temporary hair colorants do not penetrate the hair shaft itself. Instead, these dyes remain adsorbed (closely adherent) to the follicle and can be easily removed with a single shampooing. However, even temporary hair coloring agents can persist if the user''s hair is excessively dry or damaged, conditions that allow for migration of the dye from the exterior to the interior of the follicle. While temporary hair color products hold a lesser market than semi-permanent and permanent agents, they have value in that they can be easily and quickly removed without bleaching or application of a different dye.