diff --git a/homeassistant/components/group/light.py b/homeassistant/components/group/light.py
index 00b7321076f..5720948bc01 100644
--- a/homeassistant/components/group/light.py
+++ b/homeassistant/components/group/light.py
@@ -88,8 +88,8 @@ class LightGroup(GroupEntity, light.LightEntity):
         self._brightness: Optional[int] = None
         self._hs_color: Optional[Tuple[float, float]] = None
         self._color_temp: Optional[int] = None
-        self._min_mireds: Optional[int] = 154
-        self._max_mireds: Optional[int] = 500
+        self._min_mireds: int = 154
+        self._max_mireds: int = 500
         self._white_value: Optional[int] = None
         self._effect_list: Optional[List[str]] = None
         self._effect: Optional[str] = None
@@ -152,12 +152,12 @@ class LightGroup(GroupEntity, light.LightEntity):
         return self._color_temp
 
     @property
-    def min_mireds(self) -> Optional[int]:
+    def min_mireds(self) -> int:
         """Return the coldest color_temp that this light group supports."""
         return self._min_mireds
 
     @property
-    def max_mireds(self) -> Optional[int]:
+    def max_mireds(self) -> int:
         """Return the warmest color_temp that this light group supports."""
         return self._max_mireds
 
diff --git a/homeassistant/components/light/__init__.py b/homeassistant/components/light/__init__.py
index 55476c754f2..4156736f74d 100644
--- a/homeassistant/components/light/__init__.py
+++ b/homeassistant/components/light/__init__.py
@@ -407,46 +407,46 @@ class LightEntity(ToggleEntity):
     """Representation of a light."""
 
     @property
-    def brightness(self):
+    def brightness(self) -> Optional[int]:
         """Return the brightness of this light between 0..255."""
         return None
 
     @property
-    def hs_color(self):
+    def hs_color(self) -> Optional[Tuple[float, float]]:
         """Return the hue and saturation color value [float, float]."""
         return None
 
     @property
-    def color_temp(self):
+    def color_temp(self) -> Optional[int]:
         """Return the CT color value in mireds."""
         return None
 
     @property
-    def min_mireds(self):
+    def min_mireds(self) -> int:
         """Return the coldest color_temp that this light supports."""
         # Default to the Philips Hue value that HA has always assumed
         # https://developers.meethue.com/documentation/core-concepts
         return 153
 
     @property
-    def max_mireds(self):
+    def max_mireds(self) -> int:
         """Return the warmest color_temp that this light supports."""
         # Default to the Philips Hue value that HA has always assumed
         # https://developers.meethue.com/documentation/core-concepts
         return 500
 
     @property
-    def white_value(self):
+    def white_value(self) -> Optional[int]:
         """Return the white value of this light between 0..255."""
         return None
 
     @property
-    def effect_list(self):
+    def effect_list(self) -> Optional[List[str]]:
         """Return the list of supported effects."""
         return None
 
     @property
-    def effect(self):
+    def effect(self) -> Optional[str]:
         """Return the current effect."""
         return None
 
@@ -495,7 +495,7 @@ class LightEntity(ToggleEntity):
         return {key: val for key, val in data.items() if val is not None}
 
     @property
-    def supported_features(self):
+    def supported_features(self) -> int:
         """Flag supported features."""
         return 0
 
diff --git a/homeassistant/components/zwave_js/light.py b/homeassistant/components/zwave_js/light.py
index b501ecb58e7..d66821c9ba3 100644
--- a/homeassistant/components/zwave_js/light.py
+++ b/homeassistant/components/zwave_js/light.py
@@ -151,7 +151,7 @@ class ZwaveLight(ZWaveBaseEntity, LightEntity):
         return self._max_mireds
 
     @property
-    def supported_features(self) -> Optional[int]:
+    def supported_features(self) -> int:
         """Flag supported features."""
         return self._supported_features
 
diff --git a/homeassistant/util/color.py b/homeassistant/util/color.py
index 4a9162707fa..36bf47aaf96 100644
--- a/homeassistant/util/color.py
+++ b/homeassistant/util/color.py
@@ -508,12 +508,12 @@ def _get_blue(temperature: float) -> float:
     return _bound(blue)
 
 
-def color_temperature_mired_to_kelvin(mired_temperature: float) -> float:
+def color_temperature_mired_to_kelvin(mired_temperature: float) -> int:
     """Convert absolute mired shift to degrees kelvin."""
     return math.floor(1000000 / mired_temperature)
 
 
-def color_temperature_kelvin_to_mired(kelvin_temperature: float) -> float:
+def color_temperature_kelvin_to_mired(kelvin_temperature: float) -> int:
     """Convert degrees kelvin to mired shift."""
     return math.floor(1000000 / kelvin_temperature)