What process involves decolorizing with a lightener as the first step?

The process that involves decolorizing with a lightener as the first step is known as double-process haircolor. This method is particularly utilized when a dramatic color change is desired, such as going from a dark base to a much lighter shade. In double-process haircoloring, the hair is first lightened using a bleach or lightener to lift the natural pigment and then a second color is applied to create the desired tone.

This two-step approach allows for greater control over the final color result, especially when lightening significantly, as it ensures that the hair reaches the necessary level before depositing the new color. In contrast, single-process haircolor typically involves just one application of color without the initial decolorization step. Partial highlights and glazing are different processes altogether, as they do not focus on completely decolorizing the hair as a precursor to applying a new shade.