Is common use

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi teachers
Bob always acts like he’s a strong, brave guy, but when the hurricane hit he showed his true colors. He was too scared to go check on old Mrs Flowers, our next-door neighbour.

The players showed their true colours when they came back from three goals down to win the match.

Does show someone’s true colours is common use?

2

Is ‘to show someone’s true colours’ an expression in common use? (You chose the wrong verb for your question.)
Yes.