My changes...
show the ears
add a brown or silver chin strap
have the red and white stripes go all the way around his back
change belt to brown
Still not bad, like Nova said, it'll look fine on screen. Just hope the toy looks good too next to his WWII XD
Edit: I can see why they chose not to use browns though. My guess is they wanted to have a unified colour scheme(blue, red, silver) with the big 3(Thor, IM and Cap)
The only changes I would like to see are black belt and less blue on the arms, much prefer the white sleeves down to the gloves, rather than just the bicep covers