Словари
English-Azerbaijani dictionary
show oneself in one's true colours (British)
also show oneself in one's true colors (American)
to show or express one’s real character, opinion etc: He pretends to be very generous but he showed himself in his true colours/colors when he refused to give money to charity.
az: iç üzünü göstərmək
ru: предстать в истинном свете