I will take as a fact that you know at least the basics about color management, input/working/output profiles, and how not to make a complete mess with them.
But as there may be other people reading this without such a knowledge, I’ll try to explain what I understand step by step.
Let’s start with RT and it’s configuration: @ggbutcher almost nailed it, but as the documentation is a little sparse, it may lead to confusion.
You can create custom profiles, but as Rawpedia states, you have to put them in an specific folder to work with them.
In this Preferences>Color Management screenshot, I have pointed RT to a folder called icc working profiles.
The fact is that in that specific folder you have to place any icc profile you may need to use, as RT will look for it there (which may be a camera/input profile, a working profile, or an output profile).
Now to your images: to process them you must use the proper input color profile to get the correct colors your camera is able to give. Without the right input profile, you won’t get true colors. And it’s a good idea that you create you own custom camera input profile.
Then you will have to select the proper working color profile: in your case it should be ACESp0 (if I’m not wrong). It has your needed ACES primaries with a linear tone curve.
And finally you have to select the desired output color profile. For your images it should be an ACES output profile, and I would advise to use one from Elle Stone’s collection of profiles (donwload them and extract all the profiles into the folder set in the previous preferences screenshot example).
This is her explanation about her own profiles:
And here you can download the collection of profiles:
To sum up:
- you have to point RT to a folder where your custom profiles are located
- then select one of your images and edit it
- apply a neutral Processing Profile to it (to turn off every tool within RT, but Demosaicing, Exposure and Color Management)
- choose the demosaicing algorithm you like the most
- set the appropriate input profile (and that will not be an ACES profile, as there are no cameras capable of capture such range of colors)
- set the ACES working profile
- set the output profile (ideally one of Elle’s ACES profiles, as you can trust them)
- go back to the File Browser, right click the image you have just developed and copy the Processing Profile Operations
- select all the images you want to process in command line, and paste the copied Processing Profile to them
- launch the command line process with the desired options
You should get good images, but that doesn’t mean they will be the very same as Resolve gives, as it may add some hidden, beautifying processing that may please your eyes, but is not done by default by RT.
Hope this helps