What colors can lice be? - briefly
Lice are typically pale gray‑white, brown, or nearly black in color, and they may appear reddish after feeding due to the blood they have ingested.
What colors can lice be? - in detail
Lice exhibit a limited range of pigmentation that depends on species, developmental stage, and recent blood meals. Adult head lice (Pediculus humanus capitis) are typically medium‑brown to gray‑brown, with a slightly darker dorsal surface. After a recent feeding, the abdomen may appear reddish‑brown due to ingested blood, while unfed individuals look paler. Nymphs, which are immature stages, are generally lighter tan or off‑white and become progressively darker with each molt. Adult body lice (Pediculus humanus humanus) share a similar brownish hue but often appear duller, reflecting their habitat on clothing rather than on the scalp. Clothing lice (Ctenocephalides spp.) are rarely encountered on humans; when present, they are translucent to pale yellow, becoming more opaque after feeding.
Color variations arise from:
- Species‑specific pigments: melanin-like compounds give the characteristic brown tones.
- Blood content: recent meals add a reddish tint to the abdomen.
- Age and molt cycle: younger stages lack fully developed pigmentation, appearing lighter.
- Lighting and transparency: the exoskeleton’s semi‑transparent nature can make lice appear whitish or gray under bright illumination.
In laboratory observations, lice may appear almost colorless when preserved in ethanol, confirming that natural coloration is primarily due to cuticular pigments and blood. No lice are naturally green, blue, or vivid colors; any such appearance results from external staining or artifacts.