MCU: What Every Major Hero ALMOST Looked Like
Even though part of the MCU's success has always been apportioned to how well-planned the whole expanded universe was from the moment it occurred to Kevin Feige, there's enough information out there to suggest that lots of the movies came extremely close to being completely different.
There's no way Edgar Wright's Ant-Man was anything like Peyton Reed's for instance, or Jon Favreau's Iron Man 3, or Patty Jenkins' Thor 2... And Joss Whedon was always pretty clear on how different Age Of Ultron was to his intial plans. That's just how films evolve over time, and no amount of forward planning would change that.
Even on a smaller level, we've seen that the MCU almost saw some wildly different specific scenes, and even further, it seems that some of the characters who ended up in the first ten years of Marvel's tentpole franchise could have looked radically different. Sometimes that's for the better, but sometimes there are what ifs that may have even looked cooler.
Thanks to the raft of concept art that's out there now, we have a fairly good insight into what the Avengers COULD have looked like had their alternate looks been approved...
22. Captain America
Thanks to EW, we got a look at a couople of new concept art pieces both for Captain America's period look before he's frozen and the more modern look for the sequels. That blue jacket might have been striking, but he would have stood out like a sore thumb in open combat, so toning it down was a smart idea.
Meanwhile, you can see the thinking in the modern body army even without the star spangled details...
There's also another excellent alternative to the period outfit out there too combining ideas used in other costumes.
And finally, the all-black Cap outfit has to rank as one of the most egregiously overlooked concepts, while you can probably see why they didn't go for the US Agent one...