The X-wing engines were originally pink in ANH. The engine colour changed when it came to ESB & ROTJ, when they became red. But now, with Rogue One using the original colour for the engines, and the possibility of me doing an edit of R1 for personal viewing, it makes sense to have the engines the same colour throughout.
Would you change them to pink in ESB and ROTJ as well? Since the engines are pretty pink in TFA, would this not provide optimal consistency? Not that I am wanting to keep adding work on Empire but I would think that would make sense.