What is the typical role of a color filler when correcting uneven porosity across the head?

• A. To remove pigment
• B. To seal the cuticle
• C. To equalize porosity by depositing necessary pigments so the final shade is uniform.
• D. To lighten the hair further

Answer: (C)

When correcting uneven porosity, the aim is to make every strand accept color the same amount. A color filler does this by depositing the necessary pigments to fill porous gaps in the cortex and cuticle, creating a balanced base so the final shade reads uniformly across the head. By rebuilding the underlying color and filling voids, the filler eliminates the differences in how tones take up in porous versus less-porous areas, which prevents patchiness after the color is applied. If you skip the filler, highly porous zones can grab more color and end up darker or more saturated, while tougher, less porous areas take up less, leading to an uneven result. The other options don’t fit because removing pigment doesn’t address porosity differences, sealing the cuticle is more about shine and protection than equalizing uptake, and lightening further would exacerbate the mismatch rather than balance it.