cloud over
phrasal verb.to become covered with clouds, or to look sad or worried suddenly.
phrasal verb.to become overcast with clouds; figuratively, to exhibit a sudden change in facial expression reflecting sadness, anger, or anxiety.
“The sky began to cloud over before the rain started.”
“His face clouded over when he heard the news about the job cuts.”
“Although the morning began with brilliant sunshine, the horizon soon clouded over, signaling a shift in the local weather patterns.”
can be used literally for weather or figuratively for a person's mood or expression.
use the weather meaning as a visual anchor to explain the figurative meaning of a person's face 'darkening' with emotion.
this phrasal verb is intransitive and does not take a direct object or a prepositional phrase starting with 'of'.