adjective
wan
WAHN/wɑn/
Pale or faint, often suggesting weakness or tiredness.
The tired adult has a wan face above the blanket.

Etymology
Wann described darkness or lack of luster, rather than simply paleness. The connecting idea is a lack of vivid color, which came to describe the pale, unhealthy appearance associated with illness or distress.
In context
As he greeted her he noticed that she looked pale and wan. It was evident she had spent a sleepless night.