title: Why does TextBox Border Colour insist on and not changing in WPF?
body: <p>As far as I understand I should be using Style triggers to update the TextBox's border colour when it is focused. However no matter what I do it always turns to the system default blue, not the black I have specified.</p>
  
  <p>Anyone have any ideas?</p>
  
  <p>Code below:</p>
  
  <pre><code>&lt;UserControl.Resources&gt;
      &lt;Style TargetType="TextBox"&gt;
          &lt;Style.Triggers&gt;
              &lt;Trigger Property="IsFocused" Value="True"&gt;
                  &lt;Setter Property="BorderBrush" Value="Black" /&gt;
              &lt;/Trigger&gt;
          &lt;/Style.Triggers&gt;
      &lt;/Style&gt;
  &lt;/UserControl.Resources&gt;
  </code></pre>