Use ColorMode enum in iaqualink (#70510)

homeassistant/components/iaqualink/light.py

@@ -4,9 +4,8 @@ from __future__ import annotations
 from homeassistant.components.light import (
     ATTR_BRIGHTNESS,
     ATTR_EFFECT,
-    COLOR_MODE_BRIGHTNESS,
-    COLOR_MODE_ONOFF,
     DOMAIN,
+    ColorMode,
     LightEntity,
     LightEntityFeature,
 )
@@ -87,11 +86,11 @@ class HassAqualinkLight(AqualinkEntity, LightEntity):
         return list(self.dev.supported_light_effects)
 
     @property
-    def color_mode(self) -> str:
+    def color_mode(self) -> ColorMode:
         """Return the color mode of the light."""
         if self.dev.is_dimmer:
-            return COLOR_MODE_BRIGHTNESS
-        return COLOR_MODE_ONOFF
+            return ColorMode.BRIGHTNESS
+        return ColorMode.ONOFF
 
     @property
     def supported_color_modes(self) -> set[str] | None: