title: Make highlight brush the same as control brush without specifying colour
body: <p>I want to ensure that a selected ListViewItem's non-focused background is the same as the focused background.  I know that the common way of doing this is as follows:</p>
  
  <pre><code>&lt;SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Blue"/&gt;
  &lt;SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Blue"/&gt;
  </code></pre>
  
  <p>However, the problem is that I don't want to specify a colour, I merely want the Brush returned by the static resource whose key is ControlBrushKey to be the same as the one for HighlightBrushKey.</p>