DemoConsole app: The open button cannot be seen in TreeView Tasks dialog in Dark Mode

### .NET version

The latest main branch of Winforms repo

### Did it work in .NET Framework?

Not tested/verified

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

This is a regression issue, cannot reproduce on release/10.0-preview5 branch

### Issue description

In [DemoConsole](https://github.com/dotnet/winforms/tree/main/src/System.Windows.Forms/tests/IntegrationTests/DesignSurface/DemoConsole) test app of WinForms repo that the open button cannot be seen in TreeView Tasks dialog in Dark Mode


### Steps to reproduce

1. Find the sample app: [DemoConsole](https://github.com/dotnet/winforms/tree/main/src/System.Windows.Forms/tests/IntegrationTests/DesignSurface/DemoConsole) in Winforms repo
2. Change it to .NET targeting only from Multi-targets
3. Enable Dark mode by adding below code lines in the Program.cs file under DemoConsole project
```
#pragma warning disable WFO5001
Application.SetColorMode(SystemColorMode.Dark);
#pragma warning restore WFO5001
```
4. Run DemoConsole app
5. Open the TreeView Tasks dialog under Use Grid(Snap to the grid) tab
6. Observe the open button cannot be seen in TreeView Tasks dialog in Dark Mode

**More info:**
The issue can reproduce all contorls which have the open button in the Tasks dialog, such as PictureBox, DataGidView etc.