.NET version

.NET SDK 9.0.100-rc.1.24415.1 + build private dll form winforms repo release/9.0 branch

Did it work in .NET Framework?

No

Did it work in any of the earlier releases of .NET Core or .NET 5+?

This is a new feature Dark Mode: #11857

Issue description

Control pops up dialogs and MessageBox window are not in Dark mode when DarkMode enabled

ColorDialog:

FontDialog:

MessageBox:

Steps to reproduce

1. Create a WinForms .NET Core application.
2. Enable DarkMode by Application.SetColorMode(SystemColorMode.Dark) in program.cs file.
3. Add three button controls to the form designer.
4. Add click events to open FontDialog, ColorDialog and MessageBox for each of the three buttons.
5. Run the application.
6. Click each of the three buttons and observe the color of the new dialog.