Show (one's) true colours
Translation of "show (one's) true colours" into Russian
show (one's) true colours
показать (своё) истинное лицо
When the pressure mounted, he finally showed his true colours.
Когда давление возросло, он наконец-то показал своё истинное лицо.
Definitions
To reveal one's real character, intentions, or feelings, especially after having previously hidden or disguised them.