Turn on

The Turn on action extracts the predominant color from an image and turns on one or more lights set to that color. You provide the image as a web URL or as a file on the system running Home Assistant, and the action picks the most dominant color and applies it as the light’s RGB color.

Because this action then calls light.turn_on, you can also pass any valid light.turn_on options, such as brightness_pct or transition. The rgb_color is set for you from the extracted color.

Prerequisites

Before using this action, make sure any external URLs are added to allowlist_external_urls and any local file paths are added to allowlist_external_dirs. Without this, the action cannot access the image and returns an error.

Using this action from the user interface

If you prefer building automations and scripts visually, Home Assistant walks you through this action step by step. You pick what to target, tweak a few options, and save. No YAML knowledge required.

To turn on a light with an extracted color from an automation or a script:

1. Go to Settings > Automations & scenes.
2. Open an existing automation or script, or select Create automation > Create new automation.
3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
4. In the Then do section, select Add action.
5. Select what you want to control. Under By target (see Targets), select the area, floor, device, label, or light entity you want to control.
6. From the actions shown for that target, select ColorExtractor: Turn on.
7. Enter either an Image URL or an Image path, and set any of the options you need.
8. Select Save.

Options in the UI

Provide either an image URL or an image path. You cannot use both in the same action call.

Using this action in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this action as color_extractor.turn_on. A basic example looks like this:

action: color_extractor.turn_on
target:
  entity_id: light.shelf_leds
data:
  color_extract_url: "https://www.example.com/images/logo.png"

This extracts the predominant color from the image and turns on light.shelf_leds set to that color.

Options in YAML

Provide either color_extract_url or color_extract_path. The two options are mutually exclusive and cannot be used together.

Targets of the action

This action requires a target. The target is the object of the action. You can point the action at a single entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], a device, an area, a floor, or a label, and Home Assistant will run the action on every matching light entity behind that target.

• Entity: one specific light entity, such as light.living_room.
• Device: every light entity that belongs to a device.
• Area: every light entity in a room or area.
• Floor: every light entity on a floor.
• Label: every light entity that shares a label.

You can also select different target types in one action. For example, you can add a specific entity and an area as targets in the same action to run the action on both of them at once.

Good to know

• Make sure any external URL is added to allowlist_external_urls and any local file path is added to allowlist_external_dirs. Otherwise, the action cannot access the image and returns an error.
• You can pass any light.turn_on options along with this action, such as brightness_pct or transition. The RGB color is always set from the extracted color.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] without writing a line of YAML.

More examples

Real scenarios where this action shows up in automations and scripts. Copy any example and adapt it to your setup.

Automation: match shelf lights to Chromecast album art

Use this automation to set your shelf lights to the predominant color of the album art whenever it changes on a Chromecast.

• Trigger: Chromecast state changes
• Action: ColorExtractor: Turn on
  • Target: Shelf lights
  • Image URL: The Chromecast album art

- alias: "Chromecast to shelf lights"
  triggers:
    - trigger: state
      entity_id: media_player.chromecast
  actions:
    - action: color_extractor.turn_on
      target:
        entity_id: light.shelf_leds
      data:
        color_extract_url: "{{ state_attr('media_player.chromecast', 'entity_picture') }}"
        brightness_pct: 100
        transition: 5

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the action you’re calling and what you expected to happen, or share on our subreddit /r/homeassistant.

Related actions

These actions work well alongside this one:

• Get predominant color: Returns the predominant RGB color found in an image provided by URL or file path.