turn pale
When the color is washed out of a character's face because they are shocked, horrified, disgusted, scared, depressed, or otherwise drained of emotion. Can also show that the character is sick or is comedically giving up the ghost.
It is characterized by a blueish or white tint over the eyes, nose, or forehead, sometimes with vertical lines also drawn over the forehead or horizontal lines drawn over the nose.
Not to be confused with shaded face, which is when the face is literally covered in shadow.