It is not common now to find a full set of color design sheets since nobody really has any use of them, but there are tons of douga lying around in people's cel collections that had color code markings on them. So ideally if we collect enough of them, we can rebuild the color design sheets ourselves.
This is likely to be an ongoing project considering the scale of the anime. But as of now, I just want to see how far can this go. We start small and slowly build it up.
This is what a finished color design sheet would look like:

Here are some examples of color correcting Dragon Ball movies using the Goku model above:
movie 1: https://imgsli.com/MTI0Mzgx
movie 7: https://imgsli.com/MTI0Mzgy
The background color are probably wrong since I don't have reference for those yet.
So if you have any of the color design sheet or douga, please share it.
I will be updating here for new sheets or updates.