Using Light Templates to Separate Controls of R, G, B, WW & CW?

Configuration
1

I’m pretty sure this shouldn’t be too difficult but I can’t seem to find anything online for it.

I wired up an RBG/WW/CW LED controller to a load of white LED strips in my kitchen so that the different colours/temps control different areas/cupboards/under cabinets etc.

This works fine for automations (e.g. when cupboard X is opened, turn light LEDs blue just means that cupboard X’s LEDs come on and the rest go off) but can I set up template lights that control just 1 “color” and would just show up as a dimmable white light?

(Apologies if this is super obvious, but I’ve never had a need for template lights and, from my understanding, it seems to exist to group lights etc…. I.e. do the opposite of what I want! But perhaps I’m misunderstanding)

2

Perhaps this is difficult to do then?

Just to clarify, I just need to create a light entity with controllable brightness… and in turn that would control ONLY the B output of another entity.

Edit: I just had another read of the template light stuff and actually, it seems pretty easy to do but I’m sure I’m missing something:

  - platform: template
    lights:
      mirror:
        friendly_name: "Mirror"
        turn_on:
          service: light.turn_on
          data_template:
            entity_id:
              - light.bathroomblue_cupboardsred
            rgb_color:
              - 0
              - 0
              - 50
        turn_off:
          service: light.turn_off
          data_template:
            entity_id:
              - light.bathroomblue_cupboardsred
        set_level:
          service: light.turn_on
          data_template:
            brightness: "{{ brightness }}"
            entity_id: light.bathroomblue_cupboardsred
        supports_transition_template: "{{ true }}"
      cupboards:
        friendly_name: "Cupboards"
        turn_on:
          service: light.turn_on
          data_template:
            entity_id:
              - light.bathroomblue_cupboardsred
            rgb_color:
              - 50
              - 0
              - 0
        turn_off:
          service: light.turn_off
          data_template:
            entity_id:
              - light.bathroomblue_cupboardsred
        set_level:
          service: light.turn_on
          data_template:
            brightness: "{{ brightness }}"
            entity_id: light.bathroomblue_cupboardsred
        supports_transition_template: "{{ true }}"

They work just fine in isolation but if both are on they will effect each other I need “reduce redness/blueness” and an “eliminate all redness/blueness” services! Does any such thing exist!? I assume that it doesn’t in that wording at least!