pigmented

Pigmented describes anything that contains pigment, the colored substances that absorb certain wavelengths of light. In biological contexts, pigmented tissues or cells derive their color from pigments that accumulate in cells or tissues, producing a range of colors from pale yellow to deep brown or black.

In animals, the principal pigment is melanin, produced by melanocytes in the skin and hair follicles and stored in surrounding tissues. Melanin absorbs ultraviolet radiation and contributes to photoprotection as well as coloration. Other pigments—such as carotenoids, hemoproteins, and derived pigments—contribute yellows, reds, and oranges and can be dietary in origin or produced in tissues. Pigmentation patterns are shaped by genetics, hormones, age, sun exposure, and pathological conditions.

Pigmentation can be altered by disease. Hyperpigmentation refers to darkened patches caused by excess melanin or other pigments; common examples include melasma and solar lentigines. Hypopigmentation, including albinism, vitiligo, or post-inflammatory loss of pigment, results from reduced pigment production or loss of melanocytes. Some animals use pigmentation for camouflage or signaling.

In plants and some microorganisms, pigments such as chlorophyll, carotenoids, and phycobiliproteins confer color and capture light energy for photosynthesis. In biomedical contexts, pigmented structures such as the retinal pigment epithelium and neuromelanin in the brain are notable examples; lipofuscin is an age-associated pigment that accumulates in cells.

Because pigment can be diagnostic and cosmetic, descriptions of pigmentation are common in dermatology, pathology, ophthalmology, and botany. The term pigmented thus broadly covers any colored material due to pigment molecules, including endogenous pigments and externally applied dyes or stains.