What is the primary purpose of using a color filler?

The primary purpose of using a color filler is to prepare and equalize porosity. When hair is color-treated, especially after lightening or highlighting, its porosity can become uneven. This means some areas of the hair may absorb color differently than others, which can lead to a patchy or inconsistent application of the hair dye. A color filler is designed to balance out the porosity across the entire head of hair, ensuring that the dye will be absorbed evenly. This results in a more uniform and vibrant hair color, allowing the new color to be distributed evenly across all the strands.

In contrast, the other options do not address the fundamental role of a color filler. For instance, enhancing hair shine is more related to the use of finishing products rather than a filler, while sealing the hair cuticle can be done through conditioning treatments but is not the main goal of a filler. Finally, removing previous color typically involves a separate process, such as a color remover or bleach, rather than the application of a color filler.