PATHOLOGY

Detailed explanation-1: -Share on Pinterest It is a myth that deoxygenated blood is blue; all blood in the human body is red. Human blood contains hemoglobin, which is a complex protein molecule in red blood cells. Hemoglobin contains iron. The iron reacts with oxygen, giving blood its red color.

Detailed explanation-2: -Venous blood appears blue through lighter skin because of a trick that light plays on us. Through light skin, some veins look blue. Image by Niek Verlaan. The light around us has all different color wavelengths in it.