Add hex color validator (#110846)

homeassistant/helpers/config_validation.py

@@ -431,6 +431,19 @@ def icon(value: Any) -> str:
     raise vol.Invalid('Icons should be specified in the form "prefix:name"')
 
 
+_COLOR_HEX = re.compile(r"^#[0-9A-F]{6}$", re.IGNORECASE)
+
+
+def color_hex(value: Any) -> str:
+    """Validate a hex color code."""
+    str_value = str(value)
+
+    if not _COLOR_HEX.match(str_value):
+        raise vol.Invalid("Color should be in the format #RRGGBB")
+
+    return str_value
+
+
 _TIME_PERIOD_DICT_KEYS = ("days", "hours", "minutes", "seconds", "milliseconds")
 
 time_period_dict = vol.All(

tests/helpers/test_config_validation.py

@@ -1647,3 +1647,27 @@ def test_domain() -> None:
     assert cv.domain_key("hue1") == "hue1"
     assert cv.domain_key("hue 1") == "hue"
     assert cv.domain_key("hue  1") == "hue"
+
+
+def test_color_hex() -> None:
+    """Test color validation in hex format."""
+    assert cv.color_hex("#123456") == "#123456"
+    assert cv.color_hex("#FFaaFF") == "#FFaaFF"
+    assert cv.color_hex("#FFFFFF") == "#FFFFFF"
+    assert cv.color_hex("#000000") == "#000000"
+
+    msg = r"Color should be in the format #RRGGBB"
+    with pytest.raises(vol.Invalid, match=msg):
+        cv.color_hex("#777")
+
+    with pytest.raises(vol.Invalid, match=msg):
+        cv.color_hex("FFFFF")
+
+    with pytest.raises(vol.Invalid, match=msg):
+        cv.color_hex("FFFFFF")
+
+    with pytest.raises(vol.Invalid, match=msg):
+        cv.color_hex("#FFFFFFF")
+
+    with pytest.raises(vol.Invalid, match=msg):
+        cv.color_hex(123456)