title: TextBlock inside MenuItem does not became gray if MenuItem is Disabled
body: <p>If I use this code:</p>
  <pre><code>&lt;MenuItem x:Name=&quot;MenuSave&quot; Header=&quot;Save&quot; IsEnabled=&quot;False&quot;/&gt;
  </code></pre>
  <p>when <code>MenuSave</code> is disabled (in real code by a <code>RoutedUICommand</code> programmatically), the <code>Header</code> is disabled and text is gray.</p>
  <p>But if I need more text like here:</p>
  <pre><code>&lt;MenuItem x:Name=&quot;MenuSaveAs&quot; IsEnabled=&quot;False&quot;&gt;
       &lt;MenuItem.Header &gt;
              &lt;StackPanel Orientation=&quot;Horizontal&quot;&gt;
                     &lt;TextBlock Text=&quot;Save as&quot;/&gt;
                     &lt;TextBlock&gt; ...&lt;/TextBlock&gt;
              &lt;/StackPanel&gt;
       &lt;/MenuItem.Header&gt;
  &lt;/MenuItem&gt;
  </code></pre>
  <p>In this case, the <code>Header</code> is disabled but text is not gray.</p>
  <p>How can I obtain text gray with composite text?</p>
  <p>This is just simplified code to explain the problem, the real code is combination of translated terms.</p>