Synchronize States Between Two Lights

light-state-sync.yaml

blueprint:
  name: Synchronize brightness states and rgb states
  description: Synchronize the on/off state of 2 entities
  domain: automation
  input:
    entity_1:
      name: First entity
      selector:
        entity: {}
    entity_2:
      name: Second entity
      selector:
        entity: {}
  source_url: https://gist.github.com/creedda/31d391e007b978aed3879fcc1d0fb22c
mode: restart
max_exceeded: silent
variables:
  entity_1: !input entity_1
  entity_2: !input entity_2
trigger:
- platform: state
  entity_id: !input entity_1
- platform: state
  entity_id: !input entity_1
  attribute: brightness
- platform: state
  entity_id: !input entity_1
  attribute: rgb_color
  
- platform: state
  entity_id: !input entity_2
- platform: state
  entity_id: !input entity_2
  attribute: brightness
- platform: state
  entity_id: !input entity_2
  attribute: rgb_color
condition: []
action:
- choose:
    - conditions:
        condition: template
        value_template: "{{ is_state(trigger.to_state.entity_id, 'on') }}"
      sequence:
        - service: light.turn_on
          data:
            rgb_color: '{{ state_attr(trigger.to_state.entity_id, "rgb_color") }}'
            brightness: '{{ state_attr(trigger.to_state.entity_id, "brightness") }}'
            entity_id: '{% if trigger.from_state.entity_id == entity_1 %} {{ entity_2 }} {% else %} {{ entity_1 }} {% endif %}'
  default:
  - service: light.turn_off
    target:
      entity_id: '{% if trigger.from_state.entity_id == entity_1 %} {{ entity_2 }} {% else %} {{ entity_1 }} {% endif %}'

Also created a Volume Version for Media Players:
https://gist.github.com/creedda/a346d0c1ef3a883caeb7207e83ecf58c