discolors

Discolors is a term used to refer to patches or areas where the original color of a material has altered, usually due to chemical or physical change rather than painting or dyeing. It is used across disciplines to describe color changes that are unwanted or incidental.

Common causes include oxidation and corrosion; exposure to light (especially ultraviolet), heat, moisture; chemical reactions with cleaning agents or environmental pollutants; staining from contact with colored substances; biological growth such as mold; and deposition of minerals.

In metals, discoloration often appears as tarnish or oxide films. In textiles and paper, fading or brownish yellowing occurs due to light exposure and lignin oxidation. Wood may darken from tannin reactions and mineral stains. Plastics can discolor from UV weathering or heat. Food products may discolor due to enzymatic browning or oxidation.

Detection and assessment involve visual inspection, colorimetric measurements, spectroscopic techniques, and microscopy. In conservation and restoration, the stability of discolors and the risks of remediation are evaluated.

Prevention and remediation include controlling environmental factors, applying protective coatings, using stabilizers or inhibitors, and in some cases mechanical or chemical removal if feasible.

Discoloration can indicate aging, wear, or exposure history and may affect aesthetics, value, or safety in products and artworks. The term "discolors" is most often encountered in descriptive notes rather than formal terminology.