In the workflow: Scene-referred, I like using the color zones module (very visual to understand). However I just notice is it display-referred.
I’m not sure why this display-referred is in the scene-referred workflow. What would be the scene-referred sibling of this module ? (if this makes even sense)
Colour balance is the recommendation however colour zones is a “Modules to be used with care” rather than “Modules not recommended”.
Have a read of this : PIXLS.US - Darktable 3:RGB or Lab? Which Modules? Help!
In another thread I wrote this in January about the color zones module and making B&W/monochrome photos:
I can easily target many colors to get different shades of gray with color zones (or the Lightroom HSL/Color module where I can adjust 8 colors to get different shades of gray: red, orange, yellow, green, aqua, blue, purple, magenta). I guess we all know that there are actually just red, green, blue BUT having more editing choices is easier to hone in on colors that are not themselves pure red, green, or blue. Most colors are combinations of R, G, B so, personally, I find it easier to have more choices.
The color zones module with the color graph is quite nice. It would be even better if, like the tone equalizer, one could hover the mouse cursor over a color and then turn the mouse wheel to brighten/darken it though.
Something you can do though which is about as good is you can take the eyedropper and select something in the image and then a black vertical line will appear on the color graph. You can then move a node up or down along that vertical black line to adjust the shade of gray.
This thread:
Really good question, I have been pondering about the same.
While color balance would probably be the answer, I don’t see as the equivalent of the color zones.
For example:
I guess multiple instances of the Colour Balance combined with a parametric mask could help to achieve this.
Color Zones is a very visual tool, it makes it very easy to understand what you are doing.
I do hope the developers will reprogram the Color Zones module to be scene-referred (RGB) compatible.
This is a feature I would disable. Because my mouse has a surface and no scroll wheel. Swiping up, down, left and right could be very problematic.
I’m not sure that scroling on an area without clicking at the same time on the right dot is easy. Or is it ?
Some one told me in my video coment that I could also use the color balance instead of the color zone. The only way to achieve this is to clone multiple instance of the color balance for each impacted color, and adjust the Offset, Slope and Power for each (however tis is more granular).
I do hope for a scene-referred color zone module. In between, I don’t see an alternative as easy to use.
As for me, I use Color Zones quite often and also would like to eventually see the scene-referred version. I find the scene-referred workflow to be much better colorwise. Before I managed the scene-referred workflow I thought it’s a lens imperfection what spoils my colors 
Actually it wasn’t.
The same is for Gradient Filter, BTW. I use this one very often, too – to even the light or to add some volume to the scene by slightly darkening the foreground. It – well – is still OK but I believe the results would be more natural without extra colorspace conversions and with the proportional math. Yes I know it may be emulated with exposure and gradient mask but it’s a lot more fiddling, especially when mask dropout bug that… well… bugs me))
Would color look up table module be an alternative for you?
It seems to work in both color spaces depending on which one is chosen. You can also change brightness, saturation and hue of individual colors with this module.
I’m opened to any suggestions 
I will look at this module then! Tbh, I haven’t use this module yet, this will be a nice discovery.
I see it is a display-referred module, as is color zones. Will the color look-up table module be scene referred?
Actually, if it was up to me I would slightly change the behavior in the tone equalizer. I think this feature should be enabled by clicking an icon rather than be turned on automatically. Prior to 3.4 it was sort of broken because sometimes it would turn on and sometimes it wouldn’t. In 3.4 it was mostly fixed, but sometimes I find that it still won’t turn on.
Also, you can no longer just turn the mouse wheel to zoom in or zoom out. I think clicking an icon to turn on the feature and turn off the feature would be much better and more consistent with how things work throughout darktable (eyedroppers, etc.).
The problem I’ve had with color look up table is that selections are rather narrow in color range, when compared with color zones where I can adjust a wide or narrow range as needed. Color zones has always worked well for me as long as I don’t push it too hard
I feel like there is a key you can hold to allow you to zoom in the tone eq…if not clicking your scroll wheel is like a middle mouse button and will cycle between fit 100% and 200%…if that is of any use
There is nothing wrong with using the color zones module, I use it quite frequently to selectively desaturate colors.
The equivalent would probably be any module that manipulates color in the linear part of the pixelpipe, combined with some masking. Not nearly as convenient.
I would love a scene-referred version of color lookup table. It’s much quicker to use than color zones because all the HSL controls are on the same tab rather than three separate ones. But as @Dave22152 said, it seems to work in a much narrower range and quickly produces ugly effects if pushed too far.
You can control the range by selecting color patches from the image or removing them. E.g. i pick similar colors patches which i don’t want to change to anchor them and also color i want to change. It’s quick and easy.
Do you mind explaining this a bit more for how you can expand and limit the range? Say I want to work on similar shades of red but not oranges, does selecting an orange patch “anchor” it, i.e. it won’t be affected if you don’t touch the sliders? And how would I incorporate various shades of red? The color picker only takes a small area so would I select multiple red patches and adjust them individually?
Maybe I’m not using the module’s full capabilities. I’ve re-read the manual entry for it, but it doesn’t mention how to control the range.
And @s7habo, I thought it only worked in LAB space? Do you mean it can also work in RGB?
Thanks. Looks like I need to do more research because I have no idea what this means in real-world application. As far as I knew it was just a Lab module, and supposedly they don’t always play nice in a linear RGB workflow. The module is not mentioned in the “Darktable 3:RGB or Lab? Which Modules? Help!” article.
It looks like Lab only to me from that tooltip.
Hmm. I don’t know why you all have so much concern. if you put display reffered modules at the end of the pixel pipe there are no problems. I haven’t had any yet!
Besides, when the photo is done, it will be exposed in a perceptual color space anyway - in most cases.
Maybe it would be better to show which specific problems you have encountered and then we can look for a solution.