talk about their coloration ?
It is often a combination of yellow, red, brown, and black pigments, with structural colours.
Coloration
Many adult dragonflies have brilliant iridescent or metallic colours produced by structural coloration, making them conspicuous in flight. Their overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours. 
what are the life stages of a dragonfly Dragonflies are hemimetabolous insects; they do not have a pupal stage and undergo an incomplete metamorphosis with a series of nymphal stages from which the adult emerges. what are they ? It is an insect belonging to the order Odonata, infraorder Anisoptera. any conservation efforts to protect it ? In 1997, the International Union for Conservation of Nature set up a status survey and conservation action plan for dragonflies.
Overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours Many adult dragonflies have brilliant iridescent or metallic colours produced by structural coloration, making them conspicuous in flight. Their overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours. Their overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours.
Dragonfly Dragonfly Dragonfly
Coloration Coloration Coloration
Their overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours. Many adult dragonflies have brilliant iridescent or metallic colours produced by structural coloration, making them conspicuous in flight. Their overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours. Blues are typically created by microstructures in the cuticle that reflect blue light. Greens often combine a structural blue with a yellow pigment. Freshly emerged adults, known as tenerals, are often pale-coloured and obtain their typical colours after a few days, some have their bodies covered with a pale blue, waxy powderiness called pruinosity; it wears off when scraped during mating, leaving darker areas. Many adult dragonflies have brilliant iridescent or metallic colours produced by structural coloration, making them conspicuous in flight. Their overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours. 
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Dragonfly [SEP] Coloration
Many adult dragonflies have brilliant iridescent or metallic colours produced by structural coloration, making them conspicuous in flight. Their overall coloration is often a combination of yellow, red, brown, and black pigments, with structural colours. Blues are typically created by microstructures in the cuticle that reflect blue light. Greens often combine a structural blue with a yellow pigment. Freshly emerged adults, known as tenerals, are often pale-coloured and obtain their typical colours after a few days, some have their bodies covered with a pale blue, waxy powderiness called pruinosity; it wears off when scraped during mating, leaving darker areas. Some dragonflies, such as the green darner, "Anax junius", have a noniridescent blue which is produced structurally by scatter from arrays of tiny spheres in the endoplasmic reticulum of epidermal cells underneath the cuticle.