Різні рідини, різні пігменти | Different fluids, different pigments

Mammalian blood is usually red because of iron-containing hemoglobin. Insects circulate hemolymph, which is not quite the same kind of blood as vertebrate blood: it is often clear, yellowish, or greenish, though its color varies with species and pigments. Most insects do not transport oxygen in their hemolymph. In lobsters, copper-containing hemocyanin binds oxygen; oxygenated hemocyanin can give the hemolymph a blue tint. So the color comparison is broadly right but simplified: insect hemolymph is not always yellow, and the lobster’s blue tint depends on the fluid’s state.