old_contents: """Support for Tellstick lights using Tellstick Net."""
  import logging
  
  from homeassistant.components import light, tellduslive
  from homeassistant.components.light import (
      ATTR_BRIGHTNESS,
      SUPPORT_BRIGHTNESS,
      LightEntity,
  )
  from homeassistant.config_entries import ConfigEntry
  from homeassistant.core import HomeAssistant
  from homeassistant.helpers.dispatcher import async_dispatcher_connect
  from homeassistant.helpers.entity_platform import AddEntitiesCallback
  
  from .entry import TelldusLiveEntity
  
  _LOGGER = logging.getLogger(__name__)
  
  
  async def async_setup_entry(
      hass: HomeAssistant,
      config_entry: ConfigEntry,
      async_add_entities: AddEntitiesCallback,
  ) -> None:
      """Set up tellduslive sensors dynamically."""
  
      async def async_discover_light(device_id):
          """Discover and add a discovered sensor."""
          client = hass.data[tellduslive.DOMAIN]
          async_add_entities([TelldusLiveLight(client, device_id)])
  
      async_dispatcher_connect(
          hass,
          tellduslive.TELLDUS_DISCOVERY_NEW.format(light.DOMAIN, tellduslive.DOMAIN),
          async_discover_light,
      )
  
  
  class TelldusLiveLight(TelldusLiveEntity, LightEntity):
      """Representation of a Tellstick Net light."""
  
      def __init__(self, client, device_id):
          """Initialize the  Tellstick Net light."""
          super().__init__(client, device_id)
          self._last_brightness = self.brightness
  
      def changed(self):
          """Define a property of the device that might have changed."""
          self._last_brightness = self.brightness
          self._update_callback()
  
      @property
      def brightness(self):
          """Return the brightness of this light between 0..255."""
          return self.device.dim_level
  
      @property
      def supported_features(self):
          """Flag supported features."""
          return SUPPORT_BRIGHTNESS
  
      @property
      def is_on(self):
          """Return true if light is on."""
          return self.device.is_on
  
      def turn_on(self, **kwargs):
          """Turn the light on."""
          brightness = kwargs.get(ATTR_BRIGHTNESS, self._last_brightness)
          if brightness == 0:
              fallback_brightness = 100
              _LOGGER.info(
                  "Setting brightness to %d%%, because it was 0", fallback_brightness
              )
              brightness = int(fallback_brightness * 255 / 100)
          self.device.dim(level=brightness)
          self.changed()
  
      def turn_off(self, **kwargs):
          """Turn the light off."""
          self.device.turn_off()
          self.changed()
  
new_contents: """Support for Tellstick lights using Tellstick Net."""
  import logging
  
  from homeassistant.components import light, tellduslive
  from homeassistant.components.light import (
      ATTR_BRIGHTNESS,
      COLOR_MODE_BRIGHTNESS,
      LightEntity,
  )
  from homeassistant.config_entries import ConfigEntry
  from homeassistant.core import HomeAssistant
  from homeassistant.helpers.dispatcher import async_dispatcher_connect
  from homeassistant.helpers.entity_platform import AddEntitiesCallback
  
  from .entry import TelldusLiveEntity
  
  _LOGGER = logging.getLogger(__name__)
  
  
  async def async_setup_entry(
      hass: HomeAssistant,
      config_entry: ConfigEntry,
      async_add_entities: AddEntitiesCallback,
  ) -> None:
      """Set up tellduslive sensors dynamically."""
  
      async def async_discover_light(device_id):
          """Discover and add a discovered sensor."""
          client = hass.data[tellduslive.DOMAIN]
          async_add_entities([TelldusLiveLight(client, device_id)])
  
      async_dispatcher_connect(
          hass,
          tellduslive.TELLDUS_DISCOVERY_NEW.format(light.DOMAIN, tellduslive.DOMAIN),
          async_discover_light,
      )
  
  
  class TelldusLiveLight(TelldusLiveEntity, LightEntity):
      """Representation of a Tellstick Net light."""
  
      _attr_color_mode = COLOR_MODE_BRIGHTNESS
      _attr_supported_color_modes = {COLOR_MODE_BRIGHTNESS}
  
      def __init__(self, client, device_id):
          """Initialize the  Tellstick Net light."""
          super().__init__(client, device_id)
          self._last_brightness = self.brightness
  
      def changed(self):
          """Define a property of the device that might have changed."""
          self._last_brightness = self.brightness
          self._update_callback()
  
      @property
      def brightness(self):
          """Return the brightness of this light between 0..255."""
          return self.device.dim_level
  
      @property
      def is_on(self):
          """Return true if light is on."""
          return self.device.is_on
  
      def turn_on(self, **kwargs):
          """Turn the light on."""
          brightness = kwargs.get(ATTR_BRIGHTNESS, self._last_brightness)
          if brightness == 0:
              fallback_brightness = 100
              _LOGGER.info(
                  "Setting brightness to %d%%, because it was 0", fallback_brightness
              )
              brightness = int(fallback_brightness * 255 / 100)
          self.device.dim(level=brightness)
          self.changed()
  
      def turn_off(self, **kwargs):
          """Turn the light off."""
          self.device.turn_off()
          self.changed()
  
subject: Migrate tellduslive light to color_mode (#69522)