First time tipping into color correcting the op, since I know it was the hardest so I never play with it.
This scene is the worst. I couldn't figure out how they stack the layers together when filming. The yellow hair from Usagi was particularly darker than usual. If I pull the brightness of the yellow up, the yellow background on the left would be overblown, which is weird. But then when I checked on the LD version, the yellow background was also overblown...I think the way to treat it is to separate the left section from the frame, correct each separately, and then stick them back together.
The rest of the op is pretty straight forward, just need more references for the backgrounds though. For the test, I picked a shot with Sailor Moon in it, since we have her color sheet. I ran a AI upscale to clean up the grain before color correcting it. And the result looks pretty good, except for the blown up credits. Do we ever had the op without the credit?