Purple shampoo is specifically designed to neutralize and counteract unwanted brassy or yellow tones in blonde or lightened hair. It contains purple pigments that help to cancel out the warm tones and maintain a cooler, more ashy color.

If you were to use purple shampoo on pink hair, it would not have the same effect as it does on blonde hair. Purple shampoo works by targeting the yellow undertones in hair, but pink hair does not typically have these undertones. Therefore, using purple shampoo on pink hair would not effectively neutralize any unwanted tones or alter the color significantly.

However, if your pink hair has faded or turned slightly brassy over time, using a purple shampoo may help to tone down any unwanted warm tones and restore a more vibrant, cool-toned pink shade. It is important to note that the results may vary depending on the specific shade of pink and the condition of your hair.

If you are looking to maintain or enhance the vibrancy of your pink hair, it is best to use shampoos and conditioners specifically formulated for colored or dyed hair. These products are designed to be gentle and help preserve the color while providing nourishment and hydration to the hair strands.