I agree they look slightly cooler in red but unless it’s possible to change the plans to red in Rogue One, I think it’s best to keep them white in A New Hope to stay consistent with Rogue One, which is in my eyes more worth keeping consistency with than Attack of the Clones, given the higher quality of the film itself and the fact that it immediately segues into A New Hope.
I get the feeling that in the shot where R2 is plugged in and the plans show up on screen, a “software update” of sorts will show, and the white plans will change into the red ones.