Why are arteries blue?

1 Answer
Jun 20, 2017

They are not.


Arteries and veins are neither red nor blue; they are a greyish-white, if one had to ascribe a colour to them.

Arteries transport blood that is bright red due to oxygenation, while veins transport blood that is dark red because of de-oxygenation.

Under the skin, because of the differential diffusion of red and blue wavelengths of light, arteries may appear purplish and veins bluish, but that is only an optical illusion