Wearing a brightly coloured jumpsuit with a great big target on your torso probably doesn’t seem very practical from an urban camouflage point of view, but for Steve Rogers, it’s perfect. Why is he wearing the old costume? So people will know that he’s Captain America. He’s trusting that people will see him and rally around him, because that’s the whole point of Cap.
That Cap/Falcon conversation (“How do we know which ones are the bad guys?” “They’ll be the ones shooting at us.”) isn’t just a snappy one-liner, it’s a tactical decision. In a war where no one is wearing a uniform and anyone could be the enemy, Steve is consciously choosing to represent one side instead of sneaking into SHIELD headquarters in disguise. So not only will he be able to tell who the bad guys are because they’re shooting at him, everyone else will be able to tell as well. Loyal SHIELD agents will know that if you’re shooting at the dude in the red, white and blue superhero costume, then you’re the enemy.
There’s also the possibility that the vintage Captain America costume helps Bucky regain his memory for long enough to stop murdering Steve in the face. Steve’s 21st century hair, clothes and uniform would all render him well-nigh unrecogniseable to Bucky’s distant memories of their life together, which are almost entirely subsumed by the Winter Soldier’s conditioning. Cap’s old wartime costume is the only thing that stands a chance of seeming familiar.
— Costume and design in Captain America: The Winter Soldier.
Moreover, the old costume represents Steve’s reclaiming of his ideals. The new uniform, with its emphasis on SHIELD tac suit colors, embodies the moral gray areas that Steve struggles with throughout the film. He’s let himself be assimilated into SHIELD, let himself carry out missions in their name, without fully agreeing with or even understanding what they stand for. When he does figure that out, when he decides SHIELD is not something he can be a part of, he puts on the old uniform again. Because the old uniform is hokey, it is idealistic, it stands for something. Steve’s response to moral ambiguity and to arguments that the ends justify the means, is to say, loudly, visibly:
"No. I believe in something more. I believe lines can be drawn between right and wrong. You can call me naive, you can tell me the world has changed, but I believe in something better.
And yes, a stand like that will always also be a call to action. Moral ambiguity breeds apathy. It builds a world where justice is an algorithm and a push-button weapon, because who can be bothered with anything more if it’s all more or less the same? Steve takes a stand and the whole world, person by person, decides if they will shoot at him or provide air support.
(Source: hellotailor, via thetardisninja)