The DP of Rogue One Greig Fraser mentions that they had a look at the 4K versions of Star Wars AND Empire in the February issue of American Cinematographer:

“With Gareth Edwards, we wanted to be attentive that the look be consistent with A New Hope, which is seared in our brains. We weren’t necessarily trying to reproduce what it actually looked like, but how we remember it — there’s a difference between reality and the remembrance of reality. Part of our research was to look at the 4K scanned versions of A New Hope and The Empire Strikes Back. They look fantastic, but they don’t look how I remember them.”