• Is Blood Blue?"Ouch!" is Copyrighted by Flickr user: Andrew Mason (Andrew Mason) under the Creative Commons Attribution license.
  
  

Myth

• Arteries carry oxygenated blood, veins carry deoxygenated blood back to your heart. This forms the basis for the assumption that veins must be blue because deoxygenated blood is blue.
  
  

Blood Is Always Red

• It is true that your veins carry blood with lower levels of oxygen; however, according to biochemist Nick Anthis in his Scientific Activist blog, blood is never blue. Deoxygenated blood is actually deeper maroon in color.
  
  

Scientific Study

• A study published in the March 1996 issue of Applied Optics reports on the blue vein phenomenon. Alwin Kienle and his colleagues deduced three reasons for blue veins: how light is absorbed by blood, how light is reflected by your skin and the psychological mechanism of how we perceive color.
  
  

Research Details

• The Applied Optics study measured the amount of light in varying wavelengths being reflected from both imitation vessels and real blood vessels.
  
  

Light Reflection

• It is all about the ratio of blue light to red light which is being reflected. Veins one half of a millimeter or more below the skin will reflect more blue light than red, explaining why veins appear to be blue.