According to Quick Go, pigment granules are subcellular, small membrane-bounded vesicles that contain pigments or “pigment precursor molecules." The biogenesis for pigment granules is often poorly understood. This is due to the fact that these pigment granules come from a number of sources that include endosomes, lysosomes, coated vesicles and endoplasmic reticulum.
According to Ask Nature, the brilliant types of metallic colors found on damselflies' bodies are derived from a structural type of arrangement of specific pigment granules. The pigment found in the wings of certain damselflies like the species Argrion virgo is distorted from sources of light. This produces a resplendent shift in the colors blue and purple.
The pigment composition, fine structure and appearance of epidermal chromatophores found on mature Lestidae are compared and described with developing chromatophores found on mature chromatophores of the Amphipterygidae. A mature chromatophore contains a large amount near “spherical light-scattering bodies” along with large irregular shaped types of pigment vesicles. This affects the color change by the process of migrating in an opposite direction, which occurs through a system known as “interconnecting granular endoplasmic reticulum tubules." These pigment granules are a combination of ihydroxanthommatin and xanthommatin, and they have a gelatinous and liquid consistency.