diff --git a/homeassistant/components/deconz/light.py b/homeassistant/components/deconz/light.py
index 9b74008d426..077fabc6d83 100644
--- a/homeassistant/components/deconz/light.py
+++ b/homeassistant/components/deconz/light.py
@@ -244,7 +244,7 @@ class DeconzBaseLight[_LightDeviceT: Group | Light](
                     self._attr_effect_list = XMAS_LIGHT_EFFECTS
 
     @property
-    def color_mode(self) -> str | None:
+    def color_mode(self) -> ColorMode:
         """Return the color mode of the light."""
         if self._device.color_mode in DECONZ_TO_COLOR_MODE:
             color_mode = DECONZ_TO_COLOR_MODE[self._device.color_mode]