Malibu Blondes Enhancing Shampoo is a purple (violet-pigmented) shampoo made to counteract yellow and brassy tones in natural, lightened, highlighted, and gray or silver hair. As the sulfate-free formula is massaged through wet hair, its violet pigment temporarily deposits onto the hair shaft — the pigment's position opposite yellow on the color wheel is what neutralizes warmth and leaves blonde or gray hair looking cooler and brighter.
Because the toning effect comes from pigment sitting on the hair rather than altering its structure, results fade with each rinse, so it's meant to be used periodically (about once or twice a week) and alternated with a regular shampoo rather than used every wash. Malibu C markets the formula as vegan, sulfate-free, and free of parabens and added salt.