ComboBox Style Border Brush

[Kevin Marois]

I can't get the BorderBrush and BorderThickness of my ComboBoxStyle to work. Changes I make don't appear. If I change the BorderBrush to "Red", it still remains Gray. Anyone see what I'm doing wrong?

    <Setter Property="Height" Value="28"/>
    <Setter Property="UIElement.SnapsToDevicePixels" Value="True"/>
    <Setter Property="FrameworkElement.OverridesDefaultStyle" Value="True"/>
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
    <Setter Property="ScrollViewer.CanContentScroll" Value="True"/>
    <Setter Property="TextElement.Foreground" Value="Black"/>
    <Setter Property="BorderBrush" Value="Gray"/>
    <Setter Property="BorderThickness" Value="1"/>
    <Setter Property="Control.Template">
        <Setter.Value>
            <ControlTemplate TargetType="ComboBox">
                
                <Grid>
                    
                    <ToggleButton Name="ToggleButton" 
                                  Grid.Column="2"
                                  ClickMode="Press" 
                                  Focusable="False"
                                  IsChecked="{Binding Path=IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}, Mode=TwoWay}"
                                  Template="{StaticResource ComboBoxToggleButtonTemplate}"/>

                    <ContentPresenter Name="ContentSite" 
                                      Margin="5, 3, 23, 3" 
                                      IsHitTestVisible="False"
                                      HorizontalAlignment="Left" 
                                      VerticalAlignment="Center"                              
                                      Content="{TemplateBinding ComboBox.SelectionBoxItem}" 
                                      ContentTemplate="{TemplateBinding ComboBox.SelectionBoxItemTemplate}"
                                      ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"/>
                    
                    <TextBox Name="PART\_EditableTextBox" 
                             Margin="3, 3, 0, 3"
                             IsReadOnly="{TemplateBinding IsReadOnly}"
                             Visibility="Hidden</x-turndown>