diff --git a/homeassistant/util/color.py b/homeassistant/util/color.py
index 2daccf28915..3d4f7122ad0 100644
--- a/homeassistant/util/color.py
+++ b/homeassistant/util/color.py
@@ -450,7 +450,7 @@ def color_rgb_to_rgbww(
     w_r, w_g, w_b = color_temperature_to_rgb(color_temp_kelvin)
 
     # Find the ratio of the midpoint white in the input rgb channels
-    white_level = min(r / w_r, g / w_g, b / w_b)
+    white_level = min(r / w_r, g / w_g, b / w_b if w_b else 0)
 
     # Subtract the white portion from the rgb channels.
     rgb = (r - w_r * white_level, g - w_g * white_level, b - w_b * white_level)
diff --git a/tests/util/test_color.py b/tests/util/test_color.py
index db9ad988aee..d806a941965 100644
--- a/tests/util/test_color.py
+++ b/tests/util/test_color.py
@@ -366,3 +366,38 @@ def test_get_color_in_voluptuous():
         schema("not a color")
 
     assert schema("red") == (255, 0, 0)
+
+
+def test_color_rgb_to_rgbww():
+    """Test color_rgb_to_rgbww conversions."""
+    assert color_util.color_rgb_to_rgbww(255, 255, 255, 154, 370) == (
+        0,
+        54,
+        98,
+        255,
+        255,
+    )
+    assert color_util.color_rgb_to_rgbww(255, 255, 255, 100, 1000) == (
+        255,
+        255,
+        255,
+        0,
+        0,
+    )
+    assert color_util.color_rgb_to_rgbww(255, 255, 255, 1, 1000) == (
+        0,
+        118,
+        241,
+        255,
+        255,
+    )
+    assert color_util.color_rgb_to_rgbww(128, 128, 128, 154, 370) == (
+        0,
+        27,
+        49,
+        128,
+        128,
+    )
+    assert color_util.color_rgb_to_rgbww(64, 64, 64, 154, 370) == (0, 14, 25, 64, 64)
+    assert color_util.color_rgb_to_rgbww(32, 64, 16, 154, 370) == (9, 64, 0, 38, 38)
+    assert color_util.color_rgb_to_rgbww(0, 0, 0, 154, 370) == (0, 0, 0, 0, 0)