[css] Add a "Did you mean" suggestion when the value of a color is wrong but we can find a close one

tests/css/test_stylesheet.py

@@ -101,3 +101,47 @@ def test_did_you_mean_for_css_property_names(
             f'Did you mean "{expected_property_name_suggestion}"?'
         )
         assert help_text.bullets[0].markup == expected_suggestion_message
+
+
+@pytest.mark.parametrize(
+    "css_property_name,css_property_value,expected_color_suggestion",
+    [
+        ["color", "blu", "blue"],
+        ["background", "chartruse", "chartreuse"],
+        ["tint", "ansi_whi", "ansi_white"],
+        ["scrollbar-color", "transprnt", "transparent"],
+        ["color", "xkcd", None],
+    ],
+)
+def test_did_you_mean_for_color_names(
+    css_property_name: str, css_property_value: str, expected_color_suggestion
+):
+    stylesheet = Stylesheet()
+    css = """
+    * {
+      border: blue;
+      ${PROPERTY}: ${VALUE};
+    }
+    """.replace(
+        "${PROPERTY}", css_property_name
+    ).replace(
+        "${VALUE}", css_property_value
+    )
+
+    stylesheet.add_source(css)
+    with pytest.raises(StylesheetParseError) as err:
+        stylesheet.parse()
+
+    _, help_text = err.value.errors.rules[0].errors[0]  # type: Any, HelpText
+    displayed_css_property_name = css_property_name.replace("_", "-")
+    assert (
+        help_text.summary
+        == f"Invalid value for the [i]{displayed_css_property_name}[/] property"
+    )
+
+    first_bullet = help_text.bullets[0]
+    if expected_color_suggestion is not None:
+        expected_suggestion_message = f'Did you mean "{expected_color_suggestion}"?'
+        assert first_bullet.markup == expected_suggestion_message
+    else:
+        assert "Did you mean" not in first_bullet.markup