Background / Icon colour of picture glance entities

Is it possible to modify the background colour of the entities portion on a picture glance card?
I have a pretty simple card set up to switch harmony activities, but the switch buttons i use are very dim
Im hoping this is a simple case of me missing something, i have searched for hours and cannot make the icopns more prominant when switched off

  - type: vertical-stack
    cards:
      - type: picture-glance
        title: Harmony
        entities:
          - switch.watch_tv
          - switch.watch_netflix
          - switch.xbox_one
        state_image:
          "PowerOff": /local/images/harmony/power_off_red.png
          "Play Xbox One": /local/images/harmony/xbox_one_logo.png
          "Watch TV": /local/images/harmony/sky_logo.png
          "Watch Netflix": /local/images/harmony/netflix_logo.png
        entity: sensor.harmony_activity
        style: |
          ha-card {
              background-color: var(--primary-background-color);
              border-radius: 15px;
              margin: 10px;
              box-shadow:
                {% if is_state('sun.sun', 'above_horizon') %}
                  -4px -4px 8px rgba(255, 255, 255, .5), 5px 5px 8px rgba(0, 0, 0, .03);
                {% elif is_state('sun.sun', 'below_horizon') %}
                  -5px -5px 8px rgba(50, 50, 50, .2), 5px 5px 8px rgba(0, 0, 0, .08);
                {% endif %}
           }

Screenshot 2021-11-03 120133