Configuration for differently themed grafana panels (dark/light) that updates automatically according to a light level -sensor.

configuration-camera.yaml

# Set up two cameras, pulling differently themed panels from Grafana
# One dark; one light.

camera:
# Camera-card for dark theme. Note `theme=dark` in the URL.
  - platform: generic
    name: Luftfuktighet (mörk)
    still_image_url: 'http://internal.ip:port/render/d-solo/P_cth9gGz/klimat?orgId=1&refresh=10m&from=now-1d&to=now&panelId=4&theme=dark&width=500&height=325&tz=Europe%2FLondon'
    username: !secret grafana_user
    password: !secret grafana_password
# Camera-card for light theme. Note `theme=light` in the URL.
  - platform: generic
    name: Luftfuktighet (ljus)
    still_image_url: 'http://internal.ip:port/render/d-solo/P_cth9gGz/klimat?orgId=1&refresh=10m&from=now-1d&to=now&panelId=4&theme=light&width=500&height=325&tz=Europe%2FLondon'
    username: !secret grafana_user
    password: !secret grafana_password

configuration-sensor.yaml

# Set up binary sensor, used in the Lovelace conditional card.
# You could use sun.angle or whatever instead of sensor.lightlevel.

# When the binary sensor is off, light theme is used.
# When it is on, dark theme is used.

# A similar logic is used for automatically setting dark/light theme
# overall in Home assistant. Together, I get a light (or dark) themed
# Homeassistant, with grafana panels that fit the theme.

binary_sensor:
  - platform: template
    sensors:
      morkare:
        friendly_name: Light level darker than three
        # I have a setup with a custom light sensor,
        # where 0 = daylight and 5 = night. 
        # (Yes, the logic of it can be debated.)
        value_template: >-
          {{ states('sensor.lightlevel') | float > 3 }}

lovelace.yaml

# Relevant Lovelace-config for showing one card when it is light
# and another for when it is dark.

# Camera-card for dark theme
 - type: conditional
    conditions:
      - entity: binary_sensor.morkare
        state: "off"
    card:
      type: picture-entity
      name: Luftfuktighet
      entity: camera.luftfuktighet_ljus
      aspect_ratio: 1.65
      show_name: false
      show_state: false
# Camera-card for light theme
  - type: conditional
    conditions:
      - entity: binary_sensor.morkare
        state: "on"
    card:
      type: picture-entity
      name: Luftfuktighet
      entity: camera.luftfuktighet_mork
      aspect_ratio: 1.65
      show_name: false
      show_state: false