Is common use

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?

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