What is the purpose of using fillers in color correction?

• A. To seal the cuticle.
• B. To balance porosity and even out the hair's ability to take color.
• C. To remove all pigment.
• D. To deposit pigment only.

Answer: (B)

Fillers in color correction are used to create an even playing field for color uptake by balancing the hair's porosity across the strand. When hair has suffered chemical processing or has uneven porosity, some areas drink up dye much faster than others, leaving patchy results. A filler fills in the gaps in the cortex and rebuilds missing pigment so every part of the strand accepts color similarly. This gives you a uniform canvas before applying the final shade, helping prevent unexpected darkness, brassiness, or uneven tones after the color correction.

It’s not about sealing the cuticle, removing pigment, or depositing pigment alone. Sealing the cuticle is more about conditioning and protection, while removing all pigment is achieved by bleaching or stripping. Depositing pigment alone without addressing porosity can still yield uneven results, because the dye won’t uptake consistently if the hair’s porosity isn’t balanced. Fillers do both: they restore a uniform base and provide the right starting point for an even final color.