Hello,
I just went through a long strenuous testing regiment or at least it feels like it...
We were Color grading a feature the past week. Shot on RED.
The colorist graded everything and we outputed at prores 4444. And found that the color gamma would change on output to Prores 4444. Specifically the black levels would read 5% higher than it would in color.
After a lot of trial and error we found out that our colorist, found it easier on most shots of this movie to disable the RED Tab color room. When you disable this it will not export to prores 4444 properly. Giving me that drastic color shift.
This tab is automatically enabled, so that explains why we had no issues in our last project that we graded, since we never touched the tab and it wasn't our official colorist doing it.
This color shift isn't a problem in prores 422HQ.
If anyone has any questions or suggestions I didn't think of... please add them. Otherwise, I've chucked it up to being a bug and this low budget client will end up getting prores 422 HQ now. As I know it we were only pushing to be a prores 4444 and not the client.