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:
“African rights and liberty is a subject that ought to fire the breast of every free man of color in these United States, and excite in his bosom a lively, deep, decided and heart-felt interest.”
—Maria Stewart (1803–1879)
“‘Twas mercy brought me from my Pagan land,
Taught my benighted soul to understand
That there’s a God, that there’s a Saviour too:
Once I redemption neither sought nor knew.
Some view our sable race with scornful eye,
“Their color is a diabolic die.”
Remember, Christians, Negroes, black as Cain,
May be refin’d, and join th’ angelic train.”
—Phillis Wheatley (c. 1753–1784)
“The intellect,—that is miraculous! Who has it, has the talisman: his skin and bones, though they were of the color of night, are transparent, and the everlasting stars shine through, with attractive beams.”
—Ralph Waldo Emerson (1803–1882)