Answer:
Another possible interpretation may be becasue the blood begins to settle in the parts of the body that are the closest to the ground, usually the buttocks and back when a corpse is supine. The skin, normally pink-colored because of the oxygen-laden blood in the capillaries, becomes pale as the blood drains into the larger veins.
Within minutes to hours after death, the skin is discolored by livor mortis, or what embalmers call "postmortem stain," the purple-red discoloration from blood accumulating in the lowermost (dependent) blood vessels. Immediately after death, the blood is "unfixed" and will move to other body parts if the body's position is changed.
Under normal conditions, the intestinal bacteria in a corpse produce large amounts of foul-smelling gas that flows into the blood vessels and tissues. It is this gas that bloats the body, turns the skin from green to purple to black, makes the tongue and eyes protrude, and often pushes the intestines out through the vagina and rectum.
The gas also causes large amounts of foul-smelling bloodstained fluid to exude from the nose, mouth, and other body orifices.
