What does the term "double processing" refer to in hair coloring?

The term "double processing" specifically refers to the technique of using two different steps in the hair coloring process, typically involving first lightening the hair followed by applying a color. This method is often used when achieving a specific shade that requires lifting the hair's natural pigment before adding another color on top. For example, if a stylist wants to create a vibrant fashion color like pastel pink, they first need to lighten the hair to a very light blonde and then apply the pastel color to achieve the desired look.

This approach is highly effective for achieving striking and complex colors that can't be obtained through a single application method. It requires skill and knowledge of the products being used, as well as careful timing and monitoring of the hair's condition to avoid damage during the process.