In that video it is mostly RGB mixing it is not really natural color mixing that is something much more annoying.
What differs there is the GUI for the blobs. You have also a have hsv interpolation at one point which is not the best if not noticably bad. I still think hcy mixing to be better even with it’s bad use cases stated on the previous discussion thread.
I have suggested index colors for recoloring like this before.
If I knew how to make non linear gradients and metaballs i would have done a picker like this already. This presentation was already under my radar however I am not sure how much of it is possible. Maybe qt6 might have metaballs? Donno.