bilirubin, haematoidin, hematoidin - an orange-yellow pigment in the bile that forms as a product of hemoglobin; excess amounts in the blood produce the yellow appearance observed in jaundice

urobilin - brown bile pigment formed from urobilinogens and found in feces and in small amounts in urine

luciferin - pigment occurring in luminescent organisms (as fireflies); emits heatless light when undergoing oxidation

melanin - insoluble pigments that account for the color of e.g. skin and scales and feathers

pigment - dry coloring matter (especially an insoluble powder to be mixed with a liquid to produce paint etc)