What is the purpose of a color filler?

A color filler serves the important function of repigmenting or equalizing the porosity of hair to achieve uniform color results. When hair undergoes chemical processes, such as bleaching or coloring, it can develop uneven porosity, which means some parts of the hair will absorb color differently than others. A color filler helps to fill in any gaps or holes in the hair structure, allowing for a more consistent and even application of the desired hair color.

Using a color filler is particularly beneficial when transitioning from a light to a darker shade. It ensures that the underlying pigment in the hair is balanced, providing a solid foundation for the new color to adhere to. This results in a more predictable outcome, reducing the chances of having areas that appear lighter or more vibrant than others after the color application.

In contrast, the other options describe different objectives related to hair coloring but do not appropriately capture the primary function of a color filler. Lightening the hair color, removing unwanted tones, or quickly darkening the hair are not the main purposes of a color filler, which is focused on achieving an even and uniform result through proper preparation and correction of hair porosity.