I never understood the fundamentalist approach to translating comic book costumes onto the big screen. If Marvel had taken that approach to
Thor, he would have looked absolutely ridiculous (thankfully, the yellow boots, yellow belt, blue tights, and real-feathered helmet were discarded in favor of a much more
believable outfit).
Now when it comes to Captain America, I don't see why any special standard should apply. A man running around on covert missions in a bright red and blue suit is silly. The traditional costume was an important part of the story in TFA, and to some degree also in TA - but now when it comes to TWS, when Steve is not being used for WW2 propaganda or to create hope/nostalgia in a battle, it makes perfect sense that they would redesign the suit and make it more functional.