But then it should only be a small field, not the whole channel strip, so that the color contrasts don't clash, and the whole thing is still pleasant for the eye to read.
When I look at TotalMix FX (current design), it would probably be out of the question to insert an additional field for it. Because then the channel strips would become higher, and you would have to adjust some things in TotalMix FX so that the geometry is correct again. For example, the FX window, which is currently flush with the SW playback channels at the bottom.
If you had to use an existing one for this reason, it would probably be the name field, but that would possibly affect the readability of the channel names.
When I think about it, I don't think it would be easy to introduce such a design element, so as not to ruin anything in terms of design and ergonomics (especially readability for the eye).
That's why I would rather suggest you to use the already existing product features for this purpose, and the layout presets come directly to my mind.
You could use them to hide channels in the upper, middle and lower TM FX row, so that only what you want is left, for example: Vocals, Drums, etc.
The channels in the control room always remain, which is good because you will certainly have to readjust the submix in the monitoring channels.
In addition, I would recommend leaving other outputs that you need for monitoring visible in such a layout preset.
If 6 layout presets per workspace are not enough for you, you can simply clone the current workspace with its 8 snapshots/routings into several other “Workspace Quick Select”-slots.
With the key combination ALT-1 – ALT-0 you would then have 10 workspaces with 6 layout presets each, i.e., a total of up to 60 layout presets.
I think this could certainly help you to get a much better overview, maybe you'll even like it better than if the TotalMix FX window looks like a colorful parrot afterwards. Often, this is not good for the eye and the overview, and often only distracts unnecessarily.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win11Pro22H2, Cub12