There have been many discussions about what the Death Star conference room originally looked like. Some believe it should be neutral gray, while others including myself at one point have argued the case for a shade of blue, or teal. Having now seen the corrected 1977 bootleg, I believe it’s pretty much all of the above:
There are greens, and blues, and greys. Using this frame as a reference, my bluray regrade would look like this…
Bluray:
Bluray regraded: