In fact, the heroine wears all-black armor as she is forced to lead the rebellion against the Capitol.
"It's a very confusing, conflicted, complicated time for Katniss," director Francis Lawrence, who also helmed Catching Fire in addition to this and the final film, told Entertainment Weekly. "Having gone through the games one more time and having lost Peeta and having been run through the wringer, she's even more damaged. So you find her in a more agitated place. She's distraught, confused, angry."
Well, dang. Since you put it that way, we guess the mane change was totally necessary in order for J.Law to wholeheartedly tap into her dark side. Fortunately, the iconic side braid is here to stay.