What causes a grayish build-up on the hair?

A grayish build-up on the hair typically occurs because of a gradual accumulation of substances over time, which can include hair products, dirt, and environmental pollutants. This build-up can cause the hair to appear dull and discolored, leading to a grayish or ashy appearance.

Temporary hair dye, while it can affect the color of the hair, does not usually leave a consistent grayish residue. Natural hair oil, produced by the scalp, can provide moisture and sheen but does not contribute to a build-up that would appear gray. Conditioning treatments are designed to nourish and improve the hair’s texture, helping to eliminate dullness rather than contributing to a gray appearance. Therefore, the gradual accumulation of substances on the hair over time is the most accurate cause of a grayish build-up.