I'm guessing the one showing her true colors is actially the MC.
Anyway, with a title like that, I'm already having issues viewing it on a positive light, as I can't help but compare it to The Real Her.
Is the original title single or plural, though?
Singular might suggest someone finding out who they themselves really are (many a would-be Goth has discovered that they don’t actually look so great in black).
The “showing your true colors” idiom is an allusion to pirates or privateers sailing under a false flag, only to break out their actual flag once they begin the attack on the unsuspecting victim.