diff --git a/progressbar/bar.py b/progressbar/bar.py
index 01620f9..4cfc835 100644
--- a/progressbar/bar.py
+++ b/progressbar/bar.py
@@ -256,10 +256,8 @@ def _determine_enable_colors(
                     else:
                         enable_colors = progressbar.env.ColorSupport.NONE
                     break
-            else:  # pragma: no cover
-                # This scenario should never occur because `is_ansi_terminal`
-                # should always be `True` or `False`
-                raise ValueError('Unable to determine color support')
+            else:
+                enable_colors = False
 
         elif enable_colors is True:
             enable_colors = progressbar.env.ColorSupport.XTERM_256
diff --git a/progressbar/terminal/base.py b/progressbar/terminal/base.py
index b8d2a97..85971c5 100644
--- a/progressbar/terminal/base.py
+++ b/progressbar/terminal/base.py
@@ -199,7 +199,24 @@ class WindowsColors(enum.Enum):
 
     @staticmethod
     def from_rgb(rgb: types.Tuple[int, int, int]):
-        """Find the closest ConsoleColor to the given RGB color."""
+        '''
+        Find the closest WindowsColors to the given RGB color.
+
+        >>> WindowsColors.from_rgb((0, 0, 0))
+        <WindowsColors.BLACK: (0, 0, 0)>
+
+        >>> WindowsColors.from_rgb((255, 255, 255))
+        <WindowsColors.INTENSE_WHITE: (255, 255, 255)>
+
+        >>> WindowsColors.from_rgb((0, 255, 0))
+        <WindowsColors.INTENSE_GREEN: (0, 255, 0)>
+
+        >>> WindowsColors.from_rgb((45, 45, 45))
+        <WindowsColors.BLACK: (0, 0, 0)>
+
+        >>> WindowsColors.from_rgb((128, 0, 128))
+        <WindowsColors.MAGENTA: (128, 0, 128)>
+        '''
 
         def color_distance(rgb1, rgb2):
             return sum((c1 - c2) ** 2 for c1, c2 in zip(rgb1, rgb2))
@@ -211,6 +228,13 @@ def color_distance(rgb1, rgb2):
 
 
 class WindowsColor:
+    '''
+    Windows compatible color class for when ANSI is not supported.
+    Currently a no-op because it is not possible to buffer these colors.
+
+    >>> WindowsColor(WindowsColors.RED)('test')
+    'test'
+    '''
     __slots__ = 'color',
 
     def __init__(self, color: Color):
@@ -543,9 +567,6 @@ class DummyColor:
     def __call__(self, text):
         return text
 
-    def __getattr__(self, item):
-        return self
-
     def __repr__(self):
         return 'DummyColor()'
 
diff --git a/pyproject.toml b/pyproject.toml
index 04e8fcd..a6d553d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -181,6 +181,7 @@ exclude_lines = [
     'if __name__ == .__main__.:',
     'if types.TYPE_CHECKING:',
     '@typing.overload',
+    'if os.name == .nt.:',
 ]
 
 [tool.pyright]
diff --git a/tests/test_color.py b/tests/test_color.py
index bf76eec..feb962e 100644
--- a/tests/test_color.py
+++ b/tests/test_color.py
@@ -175,6 +175,7 @@ def test_colors():
             assert rgb.hex
             assert rgb.to_ansi_16 is not None
             assert rgb.to_ansi_256 is not None
+            assert rgb.to_windows is not None
             assert color.underline
             assert color.fg
             assert color.bg
@@ -304,6 +305,22 @@ def test_apply_colors(text, fg, bg, fg_none, bg_none, percentage, expected,
     )
 
 
+def test_windows_colors(monkeypatch):
+    monkeypatch.setattr(env, 'COLOR_SUPPORT', env.ColorSupport.WINDOWS)
+    assert (
+            apply_colors(
+                'test',
+                fg=colors.red,
+                bg=colors.red,
+                fg_none=colors.red,
+                bg_none=colors.red,
+                percentage=1,
+            )
+            == 'test'
+    )
+    colors.red.underline('test')
+
+
 def test_ansi_color(monkeypatch):
     color = progressbar.terminal.Color(
         colors.red.rgb,
diff --git a/tests/test_utils.py b/tests/test_utils.py
index c9d9531..2f03062 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -68,7 +68,7 @@ def test_is_ansi_terminal(monkeypatch):
     monkeypatch.delenv('PROGRESSBAR_IS_TERMINAL', raising=False)
     monkeypatch.delenv('JPY_PARENT_PID', raising=False)
 
-    assert progressbar.env.is_ansi_terminal(fd) is False
+    assert not progressbar.env.is_ansi_terminal(fd)
     assert progressbar.env.is_ansi_terminal(fd, True) is True
     assert progressbar.env.is_ansi_terminal(fd, False) is False
 
@@ -77,16 +77,16 @@ def test_is_ansi_terminal(monkeypatch):
     monkeypatch.delenv('JPY_PARENT_PID')
 
     # Sanity check
-    assert progressbar.env.is_ansi_terminal(fd) is False
+    assert not progressbar.env.is_ansi_terminal(fd)
 
     monkeypatch.setenv('PROGRESSBAR_IS_TERMINAL', 'true')
-    assert progressbar.env.is_ansi_terminal(fd) is False
+    assert not progressbar.env.is_ansi_terminal(fd)
     monkeypatch.setenv('PROGRESSBAR_IS_TERMINAL', 'false')
-    assert progressbar.env.is_ansi_terminal(fd) is False
+    assert not progressbar.env.is_ansi_terminal(fd)
     monkeypatch.delenv('PROGRESSBAR_IS_TERMINAL')
 
     # Sanity check
-    assert progressbar.env.is_ansi_terminal(fd) is False
+    assert not progressbar.env.is_ansi_terminal(fd)
 
     # Fake TTY mode for environment testing
     fd.isatty = lambda: True
@@ -103,12 +103,9 @@ def test_is_ansi_terminal(monkeypatch):
     monkeypatch.setenv('ANSICON', 'true')
     assert progressbar.env.is_ansi_terminal(fd) is True
     monkeypatch.delenv('ANSICON')
-    assert progressbar.env.is_ansi_terminal(fd) is False
+    assert not progressbar.env.is_ansi_terminal(fd)
 
     def raise_error():
         raise RuntimeError('test')
     fd.isatty = raise_error
-    if os.name == 'nt':
-        assert progressbar.env.is_ansi_terminal(fd) is None
-    else:
-        assert progressbar.env.is_ansi_terminal(fd) is False
+    assert not progressbar.env.is_ansi_terminal(fd)