Pallor mortis

[2] Pallor mortis occurs almost immediately, generally within 15–25 minutes, after death.

[2] Gravity then causes the blood to sink down into the lower parts of the body, creating livor mortis.

This can happen when blood escapes from the surface of the skin, in a matter of deep shock.

Also heart failure (insufficientia cordis) can make the face appear pale; the person then might have blue lips.

Skin can also become pale as a result of vasoconstriction as part of the body's homeostatic systems in cold conditions, or if the skin is deficient in vitamin D, as seen in people who spend most of the time indoors, away from sunlight.