Can you mix permanent hair dye with shampoo?

It is not recommended to mix permanent hair dye with shampoo. Permanent hair dye requires specific chemicals to penetrate the hair shaft and alter its color permanently. Mixing it with shampoo dilutes the dye and can affect its efficacy, leading to uneven or undesired results. It is best to follow the instructions provided with the hair dye for the best and most predictable outcome.