title: WPF combo box text color doesn't change
body: <p>I need to make the text of the combobox items in a combobox change color to white when the item is selected.  I can currently change the background color under those conditions however setting <code>&lt;Setter Property="Foreground" Value="White"/&gt;</code> inside of the same style trigger that changes the background color doesn't change anything.</p>
  
  <p><strong>Sample XAML</strong></p>
  
  <pre><code>&lt;Style x:Key="ComboBoxItemStyle" TargetType="{x:Type ComboBoxItem}"&gt;
    &lt;Style.Triggers&gt;
              &lt;Trigger Property="IsSelected" Value="True"&gt;
                  &lt;Setter Property="Background" Value="#FF648CBE"/&gt;
                  &lt;Setter Property="Foreground" Value="White"/&gt;
              &lt;/Trigger&gt;
    &lt;/Style.Triggers&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>Also, if i change the foreground setter to change the font size or boldness, that works.  I am not sure why I can do that but not change the color.</p>