Colorants

Colorants are substances used to impart color to materials. They include dyes, pigments, and specialized color agents used across industries such as textiles, food, cosmetics, paints, and printing. The term encompasses any substance that changes or imparts color and may be soluble (dyes) or insoluble (pigments).

Dyes are typically soluble and form solutions or homogeneous mixtures with the substrate, yielding uniform color. They require fibers or matrices that absorb or bond with the dissolved dye. Pigments are finely divided solids that remain dispersed or suspended; they must be bound by a binder and do not dissolve in the medium.

Colorants can be natural or synthetic. Natural colorants are derived from plants, minerals, or animal sources and are often used for traditional or specialty applications. Synthetic colorants are manufactured chemical compounds and dominate modern industries due to a wider color range, greater consistency, and lower cost.

Classification by chemistry includes inorganic colorants (for example, iron oxides and titanium dioxide) and organic colorants (such as azo dyes and quinacridone pigments). In regulatory contexts, colorants are subject to safety, purity, and labeling standards and may receive specific identifiers issued by authorities in different regions.

Applications and considerations: In foods, cosmetics, and medicines, approved colorants must meet purity specifications and labeling requirements; in textiles and plastics, colorfastness and lightfastness are critical; environmental and toxicological concerns influence sourcing and regulatory compliance.