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

1.
أظهر شخصًا على حقيقته, كشف عن حقيقة شخص
to reveal someone's true character, especially if it is negative or unpleasant
:
•
The crisis really showed him in his true colors.
الأزمة حقًا أظهرته على حقيقته.
•
His actions eventually showed him in his true colors to everyone.
أفعاله في النهاية أظهرته على حقيقته للجميع.