Pallor is the look of skin that has gone very pale — not the ordinary pale of someone who stays indoors, but a pale that makes you think of illness, shock, or fear. Doctors use it as a sign: they may notice pallor in the face, the lips, or under the eyelid. Writers like the word too, because it names the paleness as a thing, more exactly than “he went white.” Though actually, in speech almost nobody says pallor. People say someone looks pale, or as white as a sheet. Pallor belongs to hospitals, novels, and careful description. It is always a noun: a person has pallor, or you see pallor. It does not mean the person is naturally fair-skinned; it means the colour has dropped out in a way that looks wrong.