The System.Windows.SystemColors class contains a series of static properties that expose the current predefined system colors.  The properties come in triplets.  For each system color Xxx, there are XxxBrush, XxxBrushKey and XxxColor properties.

We can easily create a little WPF application to display the current system colors by building a collection of brushes and then binding the collection to a ListBox.

Here’s the final result:

Below is the code that I used to create the list.

I start with a little utility class that wraps up a named system color and its Brush:

    public class ColorInfo
    {
        public string Name { get; set; }
        public Brush Brush { get; set; }

        public ColorInfo(string name, Brush brush)
        {
            Name = name;
            Brush = brush;
        }
    }

Next, I add a collection to my main Window class, which will store a list of ColorInfo objects:

    private ObservableCollection<ColorInfo> allSystemColors;
    public ObservableCollection<ColorInfo> AllSystemColors
    {
        get { return allSystemColors; }
    }

In the window’s constructor, I populate this list, using reflection.  Notice that I iterate through all of the properties in the SystemColors class and grab only those whose names end in “Brush”.

        allSystemColors = new ObservableCollection<ColorInfo>();

        Type scType = typeof(SystemColors);
        foreach (PropertyInfo pinfo in scType.GetProperties())
        {
            if (pinfo.Name.EndsWith("Brush"))
                allSystemColors.Add(new ColorInfo(pinfo.Name.Remove(pinfo.Name.Length - 5),
                                                (Brush)pinfo.GetValue(null, null)));
        }

All that remains is to bind this collection to a ListBox.  We do this in the XAML:

    <ListBox ItemsSource="{Binding ElementName=mainWindow, Path=AllSystemColors}"
		ScrollViewer.HorizontalScrollBarVisibility="Disabled"
		ScrollViewer.VerticalScrollBarVisibility="Auto" >
    	<ListBox.ItemsPanel>
    		<ItemsPanelTemplate>
    			<WrapPanel />
			</ItemsPanelTemplate>
		</ListBox.ItemsPanel>
		<ListBox.ItemTemplate>
	        <DataTemplate>
	        	<StackPanel Orientation="Vertical">
	                <Rectangle Fill="{Binding Path=Brush}" Stroke="Black" Margin="5" StrokeThickness="1" Height="74" Width="120"/>
	                <TextBlock Text="{Binding Path=Name}" HorizontalAlignment="Center"/>
				</StackPanel>
	        </DataTemplate>
	    </ListBox.ItemTemplate>
    </ListBox>

Voila!