If blood is red, why are veins blue?

Blood is bright red in its oxygenated form and dark red in deoxygenated form. In simpler terms, it is bright red when it leaves the lungs full of oxygen and dark red when in returns to the lungs for a refill. Veins appear blue because light penetrating the skin is absorbed and reflected in high energy wavelenghts back to the eye. Higher energy wavelenghts are blue.


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