Color
(Venous blood is always blue through the opaque skin).
The appearance of veins as dark blue is a wavelength phenomenon, having to do with the reflection of blue light away from the outside of venous tissue if the vein is at 0.02 inches deep or more. Deoxygenated blood is darker than oxygenated blood due to the difference in color between deoxyhemoglobin and oxyhemoglobin.
Read more about this topic: Venous Blood
Famous quotes containing the word color:
“Good Hamlet, cast thy nighted color off.”
—William Shakespeare (1564–1616)