CustomUI - set entity theme problem

Configuration
1

Hi.
Simple thing but not working for me and I totally don’t know why.

I have a list of devices from device tracker component and I want to set device eniity color to red if this device is away. I tried almost everything but without luck.

Here is my code:

frontend:
  javascript_version: latest
  extra_html_url:
    - /local/custom_ui/state-card-custom-ui.html
  extra_html_url_es5:
    - /local/custom_ui/state-card-custom-ui-es5.html
  themes:
    red:
      primary-color: red

homeassistant:
  customize:
  ...
    sensor.wiu_l__iot_domito:
      templates:
        theme: >
          if (state === 'online') return 'red'; else return null;

What I missed?

EDIT:
I dug and dug and finally got it! :slight_smile:
instead of using:
primary-color: red
I should use:

paper-item-icon-color: red  # for icon
primary-text-color: red     # for first line of text