Meaning of the word "show someone in their true colors" in English

What does "show someone in their true colors" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

show someone in their true colors

US /ʃoʊ ˈsʌm.wʌn ɪn ðer truː ˈkʌl.ərz/
UK /ʃəʊ ˈsʌm.wʌn ɪn ðeə truː ˈkʌl.əz/
"show someone in their true colors" picture

Idiom

to reveal someone's true character, especially if it is negative or unpleasant

Example:
The crisis really showed him in his true colors.
His actions eventually showed him in his true colors to everyone.