Blue in biological organisms is RARE on Earth. Most organisms that are blue in color are in biophysics engineering — the way their structures are formed absorb all light except blue light wavelengths.
Watch the video here: https://www.pbs.org/video/why-is-blue-so-rare-in-nature-f9lv1b/
Epidermis or skin are cells with several chemicals and cellular organelles and nucleic acids to give assistance to circulatory system, organs, and immune system. In skin cells has a large macromolecular structure called melanin — a secondary metabolite created by several gene products involved in human complexion. Only true albinos lack melanin production altogether. Some skin and eye colors are created by biophysical structures, such a blue color eyes.
Humans on Earth mainly create differing molecular melanin structures to vary complexions. These are determined by genetic inheritance and epigentics.
How would it work for Chiss? They have blue skin-complexion. They are from a cold planet, Csilla. The only way humans can “acquire” a blue color is through ingestion of silver or loss of oxygen in the cold. Silver as an element combines with several compounds and chelates key essential chemical nutrients. That is why it is toxic.
Blue skin by loss of oxygen in the cold rapidly kills our species.
There is also the methyl group modifiers to be extracted through the pores of skin. It would appear splotchy.
There are 3 known blue pigments in living organisms that are through its metabolism an even blue color.
In the skin cells, in the place of melanin chemical molecules, these pigments exist. But it would be interesting if Chiss had the biophysics in their skin cells that makes their color deeper or lighter bluer as a strategic battle enhancement and is affected by the Force.