Published on 12, July, 2020
I encourage you to reply, but not more than once a day, with a interesting new fact. Let’s stretch this out instead of dumping all the interesting facts out all at once. (Btw feel free to comment on the interesting facts as much and as often as you want)
edit: posting a source for your fact is strongly encouraged.
In addition to the brown and red colouring of the skin and hair produced by the main 2 types of melanin there is a 3rd type of melanin called neuromelanin present in the brain which create a blue colouring in certain parts of the brain. The melanin itself is a sort of brown colour in bulk but because it collects in tiny granules that produce rayleigh / tyndall scattering the brain appears blue. This is the same process that irises used to make themselves blue. Interesting fact people can regain the blue colour most people have in the eyes as babies by having the brown / green pigment blasted off with a laser revealing the blue light scattering layer beneath.
PS if you ever get the chance try looking up "the 15 causes of colour" it's an excellent book.