The Alien blu-ray is one of the best looking transfers I’ve seen of a sci-fi film of that era. I’d be very pleased indeed if a new official release of the OT came out looking like that.
I heard that there were some issues with the color timing.
Aliens has some serious revisionist color timing going on.
Alien looks a little different from the earlier home video versions some grew used to, but it’s not obviously wrong the way Aliens clearly is. It’s entirely possible that it’s actually very close to what it would have looked like in 1979.
I do have a copy that was color-matched to a 90’s Laserdisc that I quite like the look of, but IMO there’s nothing actually wrong with the BR color timing for Alien.