biàn​sè

discolor

变色 (變色) biàn​sè
discolor verb
to change color or lose original color due to physical or chemical processes

This material changes color when exposed to direct sunlight.

change countenance verb
to change facial expression suddenly, typically due to anger, fear, or shock

He couldn't help but turn pale with rage upon hearing the news.

Frequency

Movie subtitles
1.10 per million appears in 1% of films
Written text
4.22 per million

Sources

Definitions
CC-CEDICT