Theme awareness for UXP - CSS and different states

Yes: The application has a property called kuiBrightnessLevel indicating the current theme. It can have the following values: 'kPanelBrightnessDarkGray' | 'kPanelBrightnessMediumGray' | 'kPanelBrightnessLightGray' | 'kPanelBrightnessOriginal'

In order to stay up-to-date, you can set up and event listener for the set event and then check if it matches a specific pattern to see if this specific settings was changed. This is how the set event descriptor would look like:

   "_obj": "set",
   "_target": [
         "_ref": "property",
         "_property": "interfacePrefs"
         "_ref": "application",
         "_enum": "ordinal",
         "_value": "targetEnum"
   "to": {
      "_obj": "interfacePrefs",
      "kuiBrightnessLevel": {
         "_enum": "uiBrightnessLevelEnumType",
         "_value": "kPanelBrightnessDarkGray"

so the handler could look like

const onSetEvent = (event, descriptor) => {
  if ( && {
    const activeTheme =