Automation for Home Assistant. Hue Light with random color, every evening 15 Minutes before sunset until 23:45. Source: https://community.home-assistant.io/t/set-a-random-color-on-a-light/73145 and https://community.home-assistant.io/t/automation-to-set-same-random-colour-on-two-hue-lights/151343

hue_automation.yaml

- alias: "Turn on light with random color"
  id: babc0ffa-622e-450a-a8c4-8dcddbb7e1f3
  initial_state: True
  trigger:
    platform: sun
    event: sunset
    offset: "-00:15:00"
  action:
    service: light.turn_on
    entity_id: light.hue_color_table_1
    data_template:
      rgb_color: ['{{ (range(0, 255)|random) }}', '{{ (range(0, 255)|random) }}', '{{ (range(0, 255)|random) }}']
      brightness_pct: 100
      transition: 1

- alias: "Turn off light"
  id: 3849265d-5834-4620-a7d4-4f35306d66df
  initial_state: True
  trigger:
    platform: time
    at: '23:45:00'
  action:
    service: light.turn_off
    entity_id: light.hue_color_table_1