Unselected tabs disappear
<p>I'm trying to fix a problem on a WPF app that was written, and seems to have worked, on Windows XP and Windows 7. On Windows 10, we're having a problem with unselected tabs disappearing.</p>

<p>The main window has a TabControl that has a custom style applied to its TabItems:</p>

<pre><code>&lt;TabItem
        x:Name="dashboardTab" 
        Header="Dashboard" 
        Style="{StaticResource mainTabStyle}" 
        &gt;
    &lt;local:DashboardControl x:Name="DashboardControl"/&gt;
&lt;/TabItem&gt;
</code></pre>

<p>The style:</p>

<pre><code>&lt;Style x:Key="mainTabStyle" TargetType="{x:Type TabItem}"&gt;
  &lt;Setter Property="Margin" Value="10,5,0,0" /&gt;
  &lt;Setter Property="Template"&gt;
    &lt;Setter.Value&gt;
      &lt;ControlTemplate TargetType="{x:Type TabItem}"&gt;
        &lt;Grid x:Name="ContentWrapper"&gt;
          &lt;ContentPresenter x:Name="ContentSite" VerticalAlignment="Bottom" HorizontalAlignment="Center" ContentSource="Header" Margin="12,2,12,2" Width="150" RecognizesAccessKey="True" /&gt;
        &lt;/Grid&gt;
        &lt;ControlTemplate.Triggers&gt;
          &lt;Trigger Property="IsSelected" Value="True"&gt;
            &lt;Setter TargetName="ContentWrapper" Property="Background" Value="AliceBlue" /&gt;
            &lt;Setter TargetName="ContentSite" Property="TextBlock.FontWeight" Value="Medium" /&gt;
            &lt;Setter TargetName="ContentSite" Property="TextBlock.Margin" Value="12,2,12,8" /&gt;
            &lt;Setter TargetName="ContentSite" Property="TextBlock.FontSize" Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type Window}}, Path=FontSize, Converter={StaticResource mathConverter}, ConverterParameter=5}" /&gt;
          &lt;/Trigger&gt;
          &lt;MultiTrigger&gt;
            &lt;MultiTrigger.Conditions&gt;
              &lt;Condition Property="IsSelected" Value="False" /&gt;
              &lt;Condition Property="IsMouseOver" Value="True" /&gt;
            &lt;/MultiTrigger.Conditions&gt;
            &lt;Setter TargetName="ContentWrapper" Property="TextBlock.Foreground" Value="Black" /&gt;
            &lt;Setter TargetName="ContentWrapper" Property="Background"&gt;
              &lt;Setter.Value&gt;
                &lt;SolidColorBrush Color="White" Opacity="0.5" /&gt;
              &lt;/Setter.Value&gt;
            &lt;/Setter&gt;
          &lt;/MultiTrigger&gt;
          &lt;MultiTrigger&gt;
            &lt;MultiTrigger.Conditions&gt;
              &lt;Condition Property="IsSelected" Value="False" /&gt;
              &lt;Condition Property="IsMouseOver" Value="False" /&gt;
            &lt;/MultiTrigger.Conditions&gt;
            &lt;Setter TargetName="ContentSite" Property="TextBlock.Foreground" Value="White" /&gt;
            &lt;Setter TargetName="ContentWrapper" Property="Background"&gt;
              &lt;Setter.Value&gt;
                &lt;SolidColorBrush Color="White" Opacity="0.15" /&gt;
              &lt;/Setter.Value&gt;
            &lt;/Setter&gt;
          &lt;/MultiTrigger&gt;
        &lt;/ControlTemplate.Triggers&gt;
      &lt;/ControlTemplate&gt;
    &lt;/Setter.Value&gt;
  &lt;/Setter&gt;
&lt;/Style&gt;
</code></pre>

<p>The idea is to change the look of the tab item headers to look less like tabs and more like a row of selection buttons.</p>

<p>If I remove the style from the TabItems, I get a perfectly ordinary looking set of tab headers. If I leave it in place, under Windows 7 it works fine. The selected tab is highlighted with a light blue background. In Windows 10, though, the unselected tabs are invisible. The foreground text seems to be white.</p>

<p>Unfortunately, our WPF expertise has walked out the door, and I'm stuck trying to fix this. I know that its this style that controls the visibility. As I said, if I remove it I get normal tab headers. If I leave it in place and change the background color from "AliceBlue" to "Red", I see the change.</p>

<p>My question: how do I change this style to apply a specified foreground color to the textblocks of unselected tabs?</p>