Many were stunned to see Paul Bettany's Vision sporting a sweater in multiple trailers of Captain America: Civil War. It was a purposeful choice made by accomplished costume designer Judianna Makovsky however, and it represents his current state of mind.
In an interview with Vulture, Makovsky revealed a bit of the thinking behind the choice.
"When I had the first meetings with [directors] Joe and Anthony Russo, we talked about the Vision trying to feel more comfortable at the Avengers compound and trying to fit in. What would that mean? We started out with him more in comfort clothes, like sweats, or something really casual. So we drew it, and it just didn't look right. It didn't go with the voice, it didn't go with the attitude."
After hitting a wall with the casual-wear, Makovsky used Stark's A.I. J.A.R.V.I.S. as a template.
"What would J.A.R.V.I.S. wear?" Makovsky mused. "I thought he would be confident and elegant in his taste, almost perfect, so we decided to look into the men of the 1940s, like Cary Grant: very simple flannel trousers, elegant cashmere sweaters." They even topped off his look with the dandiest of all affectations, an ascot: "It's sort of hidden under his shirt, but it's there."
I can totally see Vision rocking an ascot, he just has that air about him. For a character attempting to fit in, it makes sense that he would model himself after popular icons of our time, including actors like Cary Grant.
Captain America: Civil War is in theatres now.