I used to work at a facility that had one of the first 16-bit laser recorders. It was very finicky about things like humidity levels and what not. Working for this company I learned that when films are digitally remastered they are often saved back out to film masters; except not color negatives. They instead are separated into RGB* channels with each channel being recorded back to its own B&W negative. When restored from negatives, they have to scan each bit of film to be recombined for a final image. This in itself poses new issues as film behaves differently when stored for long periods of time and can actually shrink. Times 3. So the recombining of the final image can be a bit "tricky".

*I don't know if it was actually RGB or a YUV type of format. I never asked. I was just told separate color channels, and assumed RGB on my own.