What is the primary function of a color filler in hair design?

The primary function of a color filler in hair design is to equalize porosity. This process is crucial when preparing the hair for additional color treatments, especially when dealing with hair that has been previously colored or chemically altered. A color filler works by depositing a base color onto the hair to even out the porosity levels, ensuring that the hair takes on the new color more uniformly. This is particularly important because hair that varies in porosity will absorb color differently, leading to patchy or uneven results. By using a filler, a stylist can create a smooth canvas, allowing for a more consistent and vibrant final color.

Creating highlights is a different process that involves lightening specific sections of the hair rather than addressing porosity. Protecting hair and enhancing shine, while important aspects of hair care, do not relate specifically to the function of a color filler in the context of preparing hair for coloring.