I'm not against adding colour wheels, I tried to do it before. But definitely never liked any effects they create.
Can you make a color grading not changing colors, saturation, etc.? If you change anything it's already "inaccurate".
There's many things that you can change and it's still accurate, I even think you must change stuff to increase accuracy, as monitors have very little dynamic range compared to real life, and you are trying to recreate the way it really looks, but within that very limited range of brightness. I think curves/contrast are necessary, and a little saturation can be as well.
Another example - white balance. Temperatures other than 6504K on the slider makes colours not be their true values... but it only increases accuracy. The intention of white balance is to match the scene's "white" to the "white" of your surroundings (meaning your monitor's white), which is the white colour your eyes are adapted to. It lets you see the differences between colours correctly.
Found the answer in mlv_blender, xyz to rgb.
Every camera/mlv has an XYZ to (camera)RGB matrix which we must use to convert camera native RGB to any other colour space. Notice it's XYZ to RGB, so it must annoyingly be inverted first, then we can convert from XYZ to some standard RGB space like sRGB or rec2020... You can choose this in processing profile settings.
Also a L*a*b stage could be added for any processing effects that need it.
