show someone in their true colors

US /ʃoʊ ˈsʌm.wʌn ɪn ðer truː ˈkʌl.ərz/
UK /ʃoʊ ˈsʌm.wʌn ɪn ðer truː ˈkʌl.ərz/
"show someone in their true colors" picture
1.

menunjukkan sifat asli seseorang, mengungkapkan jati diri seseorang

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

:
The crisis really showed him in his true colors.
Krisis itu benar-benar menunjukkan sifat aslinya.
His actions eventually showed him in his true colors to everyone.
Tindakannya akhirnya menunjukkan sifat aslinya kepada semua orang.