>>6748Some lizards have a beautiful bright green skin colour. This vibrant green color is caused by a pigment in the lizard’s skin that is not found in many other animals. This pigment is called biliverdin and it is the same compound that gives our bruises their distinctive color.
Biliverdin is a bile pigment, produced in the liver of most animals, including humans. It is a green pigment that is normally broken down and excreted. When it comes to lizards, however, the biliverdin accumulates in their skin instead. It is believed that this is an evolutionary adaptation to help lizards blend in with their surroundings, allowing them to avoid being detected by predators.
So biologically, fantasy about orcs and goblins right, there could be humanoid intelligent beings with green skin colour.