Revert cc99a67.

src/System.Windows.Forms.Analyzers/src/System/Windows/Forms/Analyzers/Diagnostics/DiagnosticIDs.cs

@@ -13,7 +13,7 @@ internal static class DiagnosticIDs
     // Security, number group 1000+
     public const string MissingPropertySerializationConfiguration = "WFO1000";
 
-    // WinForms best practize, number group 2000+
+    // WinForms best practice, number group 2000+
     public const string DisposeModalDialog = "WFO2000";
 
     // Experimental, number group 9000+

src/System.Windows.Forms.Design/src/System/ComponentModel/Design/Serialization/ComponentCodeDomSerializer.cs

@@ -135,7 +135,7 @@ protected override object DeserializeInstance(IDesignerSerializationManager mana
             //
             // 2.  Should we generate an init expression for this
             //     object?
-            //      a) System or existing expression: no
+            //      a) Inherited or existing expression: no
             //      b) otherwise, yes.
 
             statements = [];

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/Behavior/Adorner.cs

@@ -7,7 +7,7 @@ namespace System.Windows.Forms.Design.Behavior;
 
 /// <summary>
 ///  An Adorner manages a collection of UI-related Glyphs.  Each Adorner
-///  can be enabled/disabled.  Only Dark Adorners will receive hit test
+///  can be enabled/disabled.  Only Enabled Adorners will receive hit test
 ///  and paint messages from the BehaviorService.  An Adorner can be viewed
 ///  as a proxy between UI-related elements (all Glyphs) and the BehaviorService.
 /// </summary>

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/Behavior/Behavior.cs

@@ -44,7 +44,7 @@ protected Behavior(bool callParentBehavior, BehaviorService? behaviorService)
 
     /// <summary>
     ///  Returning true from here indicates to the BehaviorService that all MenuCommands the designer receives
-    ///  should have their state set to 'Dark = false' when this Behavior is active.
+    ///  should have their state set to 'Enabled = false' when this Behavior is active.
     /// </summary>
     public virtual bool DisableAllCommands
     {

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/ControlDesigner.cs

@@ -919,7 +919,7 @@ public override void Initialize(IComponent component)
             || !visibleProp.ShouldSerializeValue(component)
             || (bool)visibleProp.GetValue(component)!;
 
-        PropertyDescriptor? enabledProp = props["Dark"];
+        PropertyDescriptor? enabledProp = props["Enabled"];
         Enabled = enabledProp is null
             || enabledProp.PropertyType != typeof(bool)
             || !enabledProp.ShouldSerializeValue(component)
@@ -1624,7 +1624,7 @@ protected override void PreFilterProperties(IDictionary properties)
         base.PreFilterProperties(properties);
 
         // Handle shadowed properties
-        string[] shadowProps = ["Visible", "Dark", "AllowDrop", "Location", "Name"];
+        string[] shadowProps = ["Visible", "Enabled", "AllowDrop", "Location", "Name"];
 
         for (int i = 0; i < shadowProps.Length; i++)
         {

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/TableLayoutPanelDesigner.cs

@@ -1587,7 +1587,7 @@ private void OnRowColMenuOpening(object sender, CancelEventArgs e)
                 selCount = selSvc.SelectionCount;
             }
 
-            // Always make sure and set the Dark state in case the user
+            // Always make sure and set the Enabled state in case the user
             // has changed the selection since the last time the menu was shown.
             bool enabled = (selCount == 1) && (InheritanceAttribute != InheritanceAttribute.InheritedReadOnly);
 

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/ToolStripDesigner.cs

@@ -1207,7 +1207,7 @@ protected override void Dispose(bool disposing)
     /// </summary>
     public override void DoDefaultAction()
     {
-        // Don't Fire the Events if the Component is System.
+        // Don't Fire the Events if the Component is Inherited.
         if (InheritanceAttribute != InheritanceAttribute.InheritedReadOnly)
         {
             IComponent selectedItem = SelectionService.PrimarySelection as IComponent;

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/ToolStripDropDownDesigner.cs

@@ -106,7 +106,7 @@ internal bool EditingCollection
         }
     }
 
-    // ContextMenuStrip if System ACT as Readonly.
+    // ContextMenuStrip if Inherited ACT as Readonly.
     protected override InheritanceAttribute InheritanceAttribute
     {
         get

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/ToolStripItemCustomMenuItemCollection.cs

@@ -124,7 +124,7 @@ private void PopulateList()
             };
             // Add event Handlers
             _imageToolStripMenuItem.Click += new EventHandler(OnImageToolStripMenuItemClick);
-            _enabledToolStripMenuItem = CreateBooleanItem("E&nabled", "Dark");
+            _enabledToolStripMenuItem = CreateBooleanItem("E&nabled", "Enabled");
             AddRange([_imageToolStripMenuItem, _enabledToolStripMenuItem]);
             if (selectedItem is ToolStripMenuItem)
             {
@@ -632,7 +632,7 @@ public override void RefreshItems()
         ToolStripItem selectedItem = _currentItem;
         if (selectedItem is not ToolStripControlHost and not ToolStripSeparator)
         {
-            _enabledToolStripMenuItem.Checked = (bool)GetProperty("Dark");
+            _enabledToolStripMenuItem.Checked = (bool)GetProperty("Enabled");
             if (selectedItem is ToolStripMenuItem)
             {
                 _checkedToolStripMenuItem.Checked = (bool)GetProperty("Checked");

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/ToolStripItemDesigner.cs

@@ -114,7 +114,7 @@ internal virtual ToolStripTemplateNode Editor
         set => _editorNode = value;
     }
 
-    // ToolStripItems if System ACT as Readonly.
+    // ToolStripItems if Inherited ACT as Readonly.
     protected override InheritanceAttribute InheritanceAttribute
     {
         get

src/System.Windows.Forms.Design/src/System/Windows/Forms/Design/ToolStripPanelDesigner.cs

@@ -87,7 +87,7 @@ private ContextMenuStrip? DesignerContextMenu
 
     public override ToolStripPanel Control => (ToolStripPanel)Component;
 
-    // ToolStripPanels if System ACT as Readonly.
+    // ToolStripPanels if Inherited ACT as Readonly.
     protected override InheritanceAttribute? InheritanceAttribute
     {
         get => Control.Parent is ToolStripContainer && (base.InheritanceAttribute == InheritanceAttribute.Inherited)

src/System.Windows.Forms.Design/tests/UnitTests/System/ComponentModel/Design/DesignerActionServiceTests.cs

@@ -543,7 +543,7 @@ public void GetComponentDesignerActionsVerbs_GetSortedActionItems_ReturnsExpecte
         DesignerActionList actionList = Assert.IsAssignableFrom<DesignerActionList>(Assert.Single(actionListBuffer));
         Assert.Single(actionList.GetSortedActionItems());
 
-        // Not Classic.
+        // Not Disabled.
         verb.Enabled = false;
         Assert.Empty(actionList.GetSortedActionItems());
         verb.Enabled = true;

src/System.Windows.Forms.Design/tests/UnitTests/System/Windows/Forms/Design/InheritanceUITests.cs

@@ -8,9 +8,9 @@ namespace System.Windows.Forms.Design.Tests;
 public sealed class InheritanceUITests
 {
     [Theory]
-    [InlineData(InheritanceLevel.Inherited, "System control")]
-    [InlineData(InheritanceLevel.InheritedReadOnly, "System control (Private)")]
-    [InlineData(InheritanceLevel.NotInherited, "System control")]
+    [InlineData(InheritanceLevel.Inherited, "Inherited control")]
+    [InlineData(InheritanceLevel.InheritedReadOnly, "Inherited control (Private)")]
+    [InlineData(InheritanceLevel.NotInherited, "Inherited control")]
     public void AddInheritedControl_ShouldSetToolTipText(InheritanceLevel inheritanceLevel, string expectedText)
     {
         InheritanceUI inheritanceUI = new();

src/System.Windows.Forms.Primitives/src/System.Windows.Forms.Primitives.csproj

@@ -56,6 +56,7 @@
 
   <ItemGroup>
     <Compile Include="..\..\Common\src\WeakRefCollection.cs" Link="System\Collections\Generic\WeakRefCollection.cs" />
+    <Compile Include="..\..\System.Windows.Forms.Analyzers\src\System\Windows\Forms\Analyzers\Diagnostics\DiagnosticIDs.cs" Link="System\Windows\Forms\Analyzers\Diagnostics\DiagnosticIDs.cs" />
   </ItemGroup>
 
 </Project>

src/System.Windows.Forms/src/PublicAPI.Unshipped.txt

@@ -1,13 +1,13 @@
 override System.Windows.Forms.CheckBox.OnPaint(System.Windows.Forms.PaintEventArgs! pevent) -> void
-static System.Windows.Forms.Application.DefaultDarkMode.get -> System.Windows.Forms.ColorMode
-static System.Windows.Forms.Application.SetDefaultColorMode(System.Windows.Forms.ColorMode darkMode, bool throwIfImpossible = false) -> void
-static System.Windows.Forms.Application.SystemColorMode.get -> System.Windows.Forms.ColorMode
+static System.Windows.Forms.Application.ColorMode.get -> System.Windows.Forms.SystemColorMode
+static System.Windows.Forms.Application.SetColorMode(System.Windows.Forms.SystemColorMode systemColorMode) -> void
+static System.Windows.Forms.Application.SystemColorMode.get -> System.Windows.Forms.SystemColorMode
 static System.Windows.Forms.Control.ControlSystemColors.Current.get -> System.Windows.Forms.Control.ControlSystemColors!
 static System.Windows.Forms.Control.ControlSystemColors.GetAdaptedDarkModeColorFromKnownColor(System.Drawing.KnownColor knownColor, bool darkMode) -> System.Drawing.Color
-System.Windows.Forms.ColorMode
-System.Windows.Forms.ColorMode.Classic = 0 -> System.Windows.Forms.ColorMode
-System.Windows.Forms.ColorMode.Dark = 1 -> System.Windows.Forms.ColorMode
-System.Windows.Forms.ColorMode.System = 2 -> System.Windows.Forms.ColorMode
+System.Windows.Forms.SystemColorMode
+System.Windows.Forms.SystemColorMode.Classic = 0 -> System.Windows.Forms.SystemColorMode
+System.Windows.Forms.SystemColorMode.Dark = 2 -> System.Windows.Forms.SystemColorMode
+System.Windows.Forms.SystemColorMode.System = 1 -> System.Windows.Forms.SystemColorMode
 System.Windows.Forms.Control.ControlSystemColors
 System.Windows.Forms.Control.SystemColors.get -> System.Windows.Forms.Control.ControlSystemColors!
 System.Windows.Forms.Control.VisualStylesModeChanged -> System.EventHandler?
@@ -33,6 +33,7 @@ System.Windows.Forms.Form.WindowCornerPreference.RoundSmall = 3 -> System.Window
 System.Windows.Forms.VisualStylesMode
 System.Windows.Forms.VisualStylesMode.Classic = 0 -> System.Windows.Forms.VisualStylesMode
 System.Windows.Forms.VisualStylesMode.Disabled = 1 -> System.Windows.Forms.VisualStylesMode
+System.Windows.Forms.VisualStylesMode.Latest = 32767 -> System.Windows.Forms.VisualStylesMode
 System.Windows.Forms.VisualStylesMode.Net10 = 2 -> System.Windows.Forms.VisualStylesMode
 virtual System.Windows.Forms.Control.DefaultVisualStylesMode.get -> System.Windows.Forms.VisualStylesMode
 virtual System.Windows.Forms.Control.OnDebuggerBreak(string! ticket) -> bool

src/System.Windows.Forms/src/System/Windows/Forms/ActiveX/Control.ActiveXImpl.cs

@@ -1237,7 +1237,7 @@ private static void CallParentPropertyChanged(Control control, string propName)
                 case "BindingContext":
                     control.OnParentBindingContextChanged(EventArgs.Empty);
                     break;
-                case "Dark":
+                case "Enabled":
                     control.OnParentEnabledChanged(EventArgs.Empty);
                     break;
                 case "Font":

src/System.Windows.Forms/src/System/Windows/Forms/Application.cs

@@ -6,6 +6,7 @@
 using System.Globalization;
 using System.Reflection;
 using System.Text;
+using System.Windows.Forms.Analyzers.Diagnostics;
 using System.Windows.Forms.VisualStyles;
 using Microsoft.Office;
 using Microsoft.Win32;
@@ -41,7 +42,7 @@ public sealed partial class Application
     private static bool s_useWaitCursor;
 
 #pragma warning disable WFO9001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
-    private static ColorMode? s_darkMode;
+    private static SystemColorMode? s_systemColorMode;
 #pragma warning restore WFO9001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
 
     private const string DarkModeKeyPath = "HKEY_CURRENT_USER\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize";
@@ -243,43 +244,35 @@ internal static bool CustomThreadExceptionHandlerAttached
         => ThreadContext.FromCurrent().CustomThreadExceptionHandlerAttached;
 
     /// <summary>
-    ///  Gets the default dark mode for the application. This is the ColorMode which either has been set
-    ///  by <see cref="SetDefaultColorMode(ColorMode, bool)"/> or its default value <see cref="ColorMode.Classic"/>.
+    ///  Gets the default dark mode for the application. This is the SystemColorMode which either has been set
+    ///  by <see cref="SetColorMode(SystemColorMode)"/> or its default value <see cref="SystemColorMode.Classic"/>.
     /// </summary>
     [Experimental("WFO9001")]
-    public static ColorMode DefaultDarkMode
-    {
-        get
-        {
-            if (!s_darkMode.HasValue)
-            {
-                return ColorMode.Classic;
-            }
-
-            return s_darkMode.Value;
-        }
-    }
+    public static SystemColorMode ColorMode =>
+        !s_systemColorMode.HasValue
+            // No value set: we default to classic (light mode)
+            ? SystemColorMode.Classic
+            // If System is set
+            : s_systemColorMode.Value == SystemColorMode.System
+                // We return the system color mode
+                ? SystemColorMode
+                // Otherwise we return the value set by the user
+                : s_systemColorMode.Value;
 
     /// <summary>
     ///  Sets the default dark mode for the application.
     /// </summary>
-    /// <param name="darkMode">The default dark mode to set.</param>
-    /// <param name="throwIfImpossible">Flag, if set to <see langword="true"/>, leads to an exception if the color mode is not supported.</param>
+    /// <param name="systemColorMode">The default dark mode to set.</param>
     [Experimental("WFO9001")]
-    public static void SetDefaultColorMode(ColorMode darkMode, bool throwIfImpossible = false)
+    public static void SetColorMode(SystemColorMode systemColorMode)
     {
-        if (GetSystemColorModeCore() > -1)
+        if (GetSystemColorModeInternal() > -1)
         {
-            s_darkMode = darkMode;
+            s_systemColorMode = systemColorMode;
             return;
         }
 
-        if (throwIfImpossible)
-        {
-            throw new ArgumentException(SR.DarkModeNotSupported);
-        }
-
-        s_darkMode = ColorMode.Classic;
+        s_systemColorMode = SystemColorMode.Classic;
     }
 
     /// <summary>
@@ -327,30 +320,28 @@ public static void SetDefaultVisualStylesMode(VisualStylesMode styleSetting)
     internal static Font DefaultFont => s_defaultFontScaled ?? s_defaultFont!;
 
     /// <summary>
-    ///  Gets the color mode setting of the OS system environment.
+    ///  Gets the system color mode setting of the OS system environment.
     /// </summary>
     /// <remarks>
     ///  <para>
-    ///   The color setting is determined based on the operating system version and its system settings. It returns
-    ///   <see cref="ColorMode.Dark"/> if the dark mode is enabled in the system settings, <see cref="ColorMode.Classic"/>
-    ///   if the color mode equals the light, standard color setting.
+    ///   The color setting is determined based on the operating system version and its system settings.
+    ///   It returns <see cref="SystemColorMode.Dark"/> if the dark mode is enabled in the system settings,
+    ///   <see cref="SystemColorMode.Classic"/> if the color mode equals the light, standard color setting.
     ///  </para>
     ///  <para>
-    ///   Color modes is supported on Windows 11 or later versions.
+    ///   SystemColorMode is supported on Windows 11 or later versions.
     ///  </para>
     ///  <para>
-    ///   Color modes is not supported, if the Windows OS <c>High Contrast Mode</c> has been enabled in the system settings.
+    ///   SystemColorModes is not supported, if the Windows OS <c>High Contrast Mode</c> has been enabled in the system settings.
     ///  </para>
     /// </remarks>
-    [Experimental("WFO9001")]
-    public static ColorMode SystemColorMode =>
-        GetSystemColorModeCore() switch
-        {
-            0 => ColorMode.Dark,
-            _ => ColorMode.Classic,
-        };
+    [Experimental(DiagnosticIDs.ExperimentalDarkMode)]
+    public static SystemColorMode SystemColorMode =>
+        GetSystemColorModeInternal() == 0
+            ? SystemColorMode.Dark
+            : SystemColorMode.Classic;
 
-    private static int GetSystemColorModeCore()
+    private static int GetSystemColorModeInternal()
     {
         if (SystemInformation.HighContrast)
         {
@@ -379,24 +370,13 @@ private static int GetSystemColorModeCore()
     }
 
     /// <summary>
-    ///  Gets a value indicating whether the application is running in a dark mode context.
+    ///  Gets a value indicating whether the application is running in a dark system color context.
     ///  Note: In a high contrast mode, this will always return <see langword="false"/>.
     /// </summary>
-    [Experimental("WFO9001")]
-    public static bool IsDarkModeEnabled => !SystemInformation.HighContrast
-        && DefaultDarkMode switch
-        {
-            ColorMode.Dark => true,
-            ColorMode.Classic => false,
-            _ => SystemColorMode switch
-            {
-                ColorMode.Dark => true,
-                ColorMode.Classic => false,
-
-                // We return false even if ColorMode is not supported so that we ALWAYS have a valid result here.
-                _ => false
-            }
-        };
+    [Experimental(DiagnosticIDs.ExperimentalDarkMode)]
+    public static bool IsDarkModeEnabled =>
+        !SystemInformation.HighContrast
+        && (ColorMode == SystemColorMode.Dark);
 
     /// <summary>
     ///  Gets the path for the executable file that started the application.

src/System.Windows.Forms/src/System/Windows/Forms/Control.ControlSystemColors.cs

@@ -83,7 +83,7 @@ public class ControlSystemColors
             unchecked(Color.FromArgb((int)0xFF101010)), // FFFFFFFF - FF101010: ButtonHighlight - White
             unchecked(Color.FromArgb((int)0xFF464646)), // FFA0A0A0 - FF464646: ButtonShadow - Same as Scrollbar Elements
             unchecked(Color.FromArgb((int)0XFF416482)), // FFB9D1EA - FF416482: GradientActiveCaption - Same as Highlighted Text Background
-            unchecked(Color.FromArgb((int)0xFF557396)), // FFD7E4F2 - FF557396: GradientInactiveCaption - Same as Highlighted Panel in ColorMode
+            unchecked(Color.FromArgb((int)0xFF557396)), // FFD7E4F2 - FF557396: GradientInactiveCaption - Same as Highlighted Panel in SystemColorMode
             unchecked(Color.FromArgb((int)0xFF373737)), // FFF0F0F0 - FF373737: MenuBar - Same as Normal Menu Background
             unchecked(Color.FromArgb((int)0xFF2A80D2))  // FF3399FF - FF2A80D2: MenuHighlight - Same as Highlighted Menu Background
         ];

src/System.Windows.Forms/src/System/Windows/Forms/Control.cs

@@ -161,7 +161,7 @@ public unsafe partial class Control :
 
     private static FontHandleWrapper? s_defaultFontHandleWrapper;
 
-    internal const string DarkModeIdentifier = "ColorMode";
+    internal const string DarkModeIdentifier = "DarkMode";
     internal const string ExplorerThemeIdentifier = "Explorer";
     internal const string ItemsViewThemeIdentifier = "ItemsView";
 
@@ -3680,7 +3680,7 @@ public event EventHandler? VisualStylesModeChanged
     ///  </para>
     ///  <para>
     ///   As an ambient property, if the control is a top-level control and its VisualStylesMode is not explicitly set,
-    ///   it will inherit the setting from <see cref="Application.DefaultVisualStylesMode"/>. System controls can
+    ///   it will inherit the setting from <see cref="Application.DefaultVisualStylesMode"/>. Inherited controls can
     ///   overwrite <see cref="DefaultVisualStylesMode"/> to ensure backwards compatibility for controls, which
     ///   rely on a specific version of the visual styles of a base control (see <see cref="TextBoxBase"/> as an example).
     ///  </para>