title: WPF SystemColors: color of TextBox border
body: <p>I am trying to make a search TextBox with an embedded magnifying glass icon. I have the following markup so far:</p>
  
  <pre><code>&lt;Border DockPanel.Dock="Bottom" Margin="2,4,0,4" 
          BorderThickness="1" SnapsToDevicePixels="True" 
          BorderBrush="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"&gt;
      &lt;DockPanel&gt;
          &lt;StackPanel Orientation="Horizontal" DockPanel.Dock="Right"&gt;
              &lt;Image Source="/Resources/search-13x13.png" Width="13"/&gt;
          &lt;/StackPanel&gt;
          &lt;TextBox Name="searchTextBox" DockPanel.Dock="Bottom" BorderThickness="0" 
                   Text="{Binding FilterText, UpdateSourceTrigger=PropertyChanged}"/&gt;
      &lt;/DockPanel&gt;
  &lt;/Border&gt;
  </code></pre>
  
  <p>However, I can't find the entry in SystemColors which will give me the same color as the standard TextBox border. This is a blueish color by default. Am I being really stupid here?!?</p>
  
  <p>EDIT: btw, the image is contained in a stackpanel because I'm planning to put a dropdown arrow in there as well.</p>