What is a key difference between temporary and permanent hair color?

The key difference between temporary and permanent hair color lies in their formulation and how they interact with the hair structure. Temporary color is designed to coat the outer layer of the hair shaft and does not penetrate deeply into the hair. This means that it can wash out after several shampoos, typically lasting from a few washes to about 6-8 weeks, depending on the product and frequency of washing.

In contrast, permanent hair color contains a developer that allows the dye to penetrate the hair shaft and change the natural color of the hair. Once applied, permanent color provides a more lasting change and does not wash out, although it may fade over time due to environmental factors and hair care practices.

Understanding this distinction is crucial for cosmetologists when selecting products for clients, as it influences both the desired outcome and the maintenance required for the chosen color.