In this case it’s not a problem of the bluray, but an issue of correcting the print. I can match the 70 mm print colors, as is evident from the previous page of this thread. The problem is that the print has a pronounced green shift, that has to be corrected for the regrade. The question is, how much green do you remove? This requires extensive examining of other references, such as the frame you posted. Often something will seem a major improvement, but then while examining more references, the inconsistencies with some of these references become difficult to ignore, and it’s back to the drawing board. The bluray has many issues, and so do the references. Getting a clear picture of how you believe it should look takes time, and a lot of hits and misses.