What is a common indicator of over-processing during color application?

In the context of hair coloring, over-processing occurs when the hair is subjected to excessive chemical treatment, which can lead to damaged and compromised hair structure. Increased porosity and brittleness are key indicators of this condition because over-processing alters the hair's cuticle, making it more porous. This higher porosity means the hair cuticles are more open and cannot retain moisture effectively, leading to dryness and brittleness.

When hair has been over-processed, it often absorbs color more quickly, which is a sign that the cuticle is damaged. However, while quick absorption of color might be an indicator of porosity, the ultimate manifestation of the damage is the brittle and fragile condition of the hair. Shiny hair typically indicates good health, and no change in texture suggests that the hair has not been affected by any chemical treatments, making those options irrelevant as indicators of over-processing. Thus, increased porosity and brittleness serve as the most clear and direct signs of over-processing in the context of hair coloring.