The only context under which I've witnessed it used directly with my own eyes and ears in person and not recorded were scenarios when a manipulative person was trying to coerce obedience in another. The manipulative, abusive individual accuses their victim / target of having "true colors" of a malign variety in order to attempt to motivate them to change their behavior as a defensive reflex to show the manipulator is wrong about them.

It's gaslighting, projection, and DARVO all the way down...