"Conform", "Refine" color palette

Hello all! I have an interesting color grading need that I haven't seem to found any solutions to, even though I think it would be a very useful technique.

I've read a lot about refining color palettes to reduce the amount of different hues in a scene as well as matching hues to a color palette (it looks more professional and Hollywood-ish - in an extreme example, Grand Budapest Hotel). A lot of that comes in during production design, costume design, and the way it's lit/shot, but I know color grading can really bring everything together and make it cohesive. Especially in regards to reducing the number of different hues.

Essentially what I'm trying to do is reduce the amount of hues in a scene by rounding all hues in a certain range - say, 1-20 - to a specific palette color - say, 14 - whilst leaving saturation and luminosity untouched. Ideally, every possible range of hues would be rounded to the 4 or 5 different hues I have in my color palette - i.e. hue value ranges 1-50, 51-100, 101-150, 151-200, and 201-255 assigned to 23, 75, 124, 155, and 220, respectively, or something like that.

It would also be interesting if it was possible to automatically round to a specific palette hue instead of predefining a range to be rounded. Another cool ability would be to define tolerance and "feathering", or how rigidly it rounds to a specific palette color.

If this is possible, I feel like this would be a really neat way to wrangle competing hues in a scene, match a predefined color palette, and/or establish a mood very quickly. I'm also assuming this would be a final-step grading procedure in one's pipeline. I'm very new to Resolve, but I've recently engaged it for this and other very technical grading needs.

Thank you for any light you can shed on my curiosity!

If I'm reading this correctly, its similar to a feature that will be released in V14 called "color compressor."

jPo, CSI

Yes indeed its a very cool new Davinci Resolve OFX called "Color Compressor".
An alternative for DR 12.5.6 or also for 14 as has slightly larger feature set is using one of Paul Dore's cool free OFX plugins called "Hue Converge".
mac : https://github.com/baldavenger/macOS-OFX
win : https://github.com/baldavenger/Win-OFX
linux : https://github.com/baldavenger/Linux-OFX

It will do exactly what you want.

I've been exploring this too, and 3D LUT creator seems to be a powerful tool, there is an example on utube where he takes a street scene and limits the colour to tame the scene.
youtu.be/3tyYjsYUrww
Above is the intro video

Wow, that's awesome! Both of those options look like it's exactly what I'm describing. Ironic that the update is right around the corner. It's like they read our minds...

I have used this feature for special occasions, but be warned that sometimes there are weird artifacts when you force specific pixels to a color they were never meant to have, particularly under changing lighting.

I have had better luck with the Color Gamut ResolveFX plug in, which helps avoid out-of-gamut errors with tricky situations like clipped car tail lights or traffic lights. These can help even more than a precisely-qualified key in some cases.

Tnx for the tip Marc, will have a more detailed look at it. So far just thought is was more used in conjunction with colorspace transforms.