How to Set WPF Checkbox Text Colo to Gray if Disabled?

In WPF, when a checkbox is disabled, only the box is grayed out. The text of the checkbox remains black (the default color). How do I make the text also grayed out when checkbox is disabled? The following is the style xaml I've used. The last trigger only changes the box border color, not the text. Target or property does not recognize "Textblock" or "Content". Please help!

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

<ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="/LightZ;component/Palettes/Brushes.xaml" />
    <ResourceDictionary Source="/LightZ;component/Styles/FillBrush.xaml" />
</ResourceDictionary.MergedDictionaries>

<Style x:Key="CheckBoxFocusVisual">
    <Setter Property="Control.Template">
        <Setter.Value>
            <ControlTemplate>
                <Border>
                    <Rectangle 
        Margin="15,0,0,0"
        StrokeThickness="1"
        Stroke="#60000000"
        StrokeDashArray="1 2"/>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<Style x:Key="{x:Type CheckBox}" TargetType="CheckBox">
    <Setter Property="SnapsToDevicePixels" Value="true"/>
    <Setter Property="OverridesDefaultStyle" Value="true"/>
    <Setter Property="FocusVisualStyle"    Value="{StaticResource CheckBoxFocusVisual}"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="CheckBox">
                <BulletDecorator Background="Transparent">
                    <BulletDecorator.Bullet>
                        <Border x:Name="Border"  
          Width="15" 
          Height="15" 
          CornerRadius="0" 
          Background="Transparent"
          BorderThickness="1"
          BorderBrush="{StaticResource text}">
                            <Path 
            Width="12" Height="12" 
            x:Name="CheckMark"
            SnapsToDevicePixels="False" 
            Stroke="{StaticResource text}"
            StrokeThickness="2"
            Data="M 0 5 L 3 10 10 0" />
                        </Border>
                    </BulletDecorator.Bullet>
                    <ContentPresenter Margin="4,0,0,0"
        VerticalAlignment="Center"
        HorizontalAlignment="Left"
        RecognizesAccessKey="True"/>
                </BulletDecorator>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsChecked" Value="false">
                        <Setter TargetName="CheckMark" Property="Visibility" Value="Collapsed"/>
                    </Trigger>
                    <Trigger Property="IsChecked" Value="{x:Null}">
                        <Setter TargetName="CheckMark" Property="Data" Value="M 0 7 L 7 0" />
                    </Trigger>
                    <Trigger Property="IsMouseOver" Value="true">
                        <Setter TargetName="Border" Property="Background" Value="{StaticResource highlight}" />
                        <Setter TargetName="CheckMark" Property="Stroke" Value="{StaticResource highlighttext}" />
                    </Trigger>
                    <Trigger Property="IsPressed" Value="true">
                        <Setter TargetName="Border" Property="Background" Value="{StaticResource PressedBrush}" />
                        <Setter TargetName="Border" Property="BorderBrush" Value="{StaticResource PressedBorderBrush}" />
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter TargetName="Border" Property="Background" Value="{StaticResource DisabledBackgroundBrush}" />
                        <Setter TargetName="Border" Property="BorderBrush" Value="{StaticResource DisabledBorderBrush}" />
                        <Setter Property="Foreground" Value="{StaticResource DisabledForegroundBrush}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>