Slider entity row colour in a custom button

This is driving me crazy.

How can I control the colour of a slider if its a custom field within a custom button card?

This is my config for the button, I have card mod installed but cannot work out what to put in to change the colour of the slider:

      - type: custom:button-card
        styles:
          card:
            - box-shadow: none;
            - overflow: unset
          name:
            - color: white
          label:
            - color: yellow
          grid:
            - grid-template-areas: '"n" "i" "l" "slider"'
            - grid-template-columns: 1fr
            - grid-template-rows: min-content fr min-content min-content
        size: 40%
        state:
        - value: "off"
          styles:
            icon:
              - color: white
        - value: "on"
          styles:
            icon:
              - color: yellow
        - value: "unavailable"
          styles:
            icon:
              - color: red
        custom_fields:
          slider:
            card:          
              full_row: true
              hide_state: true
              type: custom:slider-entity-row
              entity: light.hue_filament_bulb_1
            overflow: unset
            filter: opacity(80%)
        entity: light.hue_filament_bulb_1
        name: tak
        icon: mdi:lightbulb