To reveal what one really believes, thinks, or wants, or the true nature or strength of their character. (Usually, but not always, used in reference to someone with bad or unpleasant beliefs, desires, or characteristics.) The undercover journalist secretly filmed her meeting with the CEO, showing him in his true colors as a money-hungry snake with no regard for the law. The defendant's attorneys brought in a multitude of character witnesses to show her in her true colors—a kind, compassionate woman with no motive for revenge.