Theory: A reason Marvel changed their looks for Infinity War

Everyone looks cool and badass (at least serious) and then there is Hawkeye

I thought it was because they were on the run

Or it could just be character development. Chris Hemsworth was tired of the wig so he was able to convince Marvel to let his real hair show for Thor 3.

i dont really like the blonde hair for black widow tbh, i prefer the ginger over it

Pretty sure Avengers 4 take place in the past so this is a plausible theory