Blink/flash neopixelbus lights whenever they are on

Seems like this would be simple, but I just want my neopixelbus lights to flash when they are turned on.

light:
  - platform: neopixelbus
    type: GRB
    pin: GPIO3
    variant: WS2812
    num_leds: 4
    name: "Downstairs DND Light"
    id: downstairs_dnd_light

I’ve tried a bunch of stuff using the on_turn_on and flash_length to no avail.

What is the best approach here? I still want to be able to control the color of the LEDs.

This works fine for me. I’m not sure how the flash_length works.

light:
  - platform: fastled_clockless 
    on_turn_on:
      then:
        - light.turn_on: 
            id: downstairs_dnd_light
            brightness: 50%
            effect: Flashing
    chipset : WS2812B
    rgb_order: GRB
    id: downstairs_dnd_light
    internal: False
    pin: GPIO3
    num_leds: 4
    name: "Downstairs DND Light"
    effects:
      - strobe:
          name: Flashing
          colors:
            - state: True
              red: 100%
              green: 100%
              blue: 100%
              duration: 1000ms
            - state: False
              duration: 1000ms

Perfect thank you!