What does a conditioner filler do during hair coloring?

A conditioner filler serves a specific purpose in the hair coloring process, particularly for damaged or overly porous hair. When hair is overly porous, it can absorb color unevenly, leading to inconsistent results such as blotchiness or fading. The filler helps to recondition the hair, filling in gaps in the hair structure and creating a more uniform surface for color application.

By improving the condition of the cuticle and ensuring a more balanced moisture level, a conditioner filler allows for a smoother, more even application of color. This ultimately results in a more vibrant and consistent final color. While the other options each refer to aspects of color treatment or enhancement, they do not focus on the primary function of the filler in addressing hair's porosity and damage, which is essential for achieving the best results during the coloring process.