why are our veins blue and our blood red.

Question: why are our veins blue and our blood red.
- Keywords:
  blood,
  blue,
  red,
  veins
Asked by chiara728 to Ed, Sam, Steve on 23 Jun 2011.
- Steven Daly answered on 23 Jun 2011:
  
  This is because of the pigmentation we have in our veins, and I am not really sure there is a particular reason they are blue. It is the veins themselves, rather than the blood that is blue though. Blood is always some shade of red, because it contains iron(II), which is iron with two electrons removed, and this is red. It is actually the same thing that makes rust red!
- Sam Tazzyman answered on 23 Jun 2011:
  
  I learnt this the other day on this website! I never knew before that it was the veins that were blue. As for why the veins are blue, as Ed often stresses on this site, everything has to be some colour, there doesn’t necessarily have to be a reason for it.

Question: why are our veins blue and our blood red.