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:
“Actors work and slave—and it is the color of your hair that can determine your fate in the end.”
—Helen Hayes (1900–1993)
“All our Concord waters have two colors at least; one when viewed at a distance, and another, more proper, close at hand.... Walden is blue at one time and green at another, even from the same point of view. Lying between the earth and the heavens, it partakes of the color of both.”
—Henry David Thoreau (1817–1862)