Checkbox style Foreground color not changing although style definded

Please see this Checkbox style:

<Style TargetType="{x:Type CheckBox}">
    <Setter Property="SnapsToDevicePixels" Value="true" />
    <Setter Property="OverridesDefaultStyle" Value="true" />
    <Setter Property="Height" Value="20" />
    <Setter Property="FocusVisualStyle" Value="{DynamicResource MyFocusVisualStyte}" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type CheckBox}">
                <BulletDecorator>
                    <BulletDecorator.Bullet>
                        <Grid Height="{TemplateBinding Height}"
                                  Width="{Binding RelativeSource={RelativeSource Self}, Path=Height, UpdateSourceTrigger=PropertyChanged}"
                                  MinHeight="20"
                                  MinWidth="20"
                                  ShowGridLines="False">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="4*" />
                                <ColumnDefinition Width="1*" />
                                <ColumnDefinition Width="1*" />
                                <ColumnDefinition Width="4*" />
                                <ColumnDefinition Width="1*" />
                                <ColumnDefinition Width="1*" />
                                <ColumnDefinition Width="2*" />
                                <ColumnDefinition Width="2*" />
                            </Grid.ColumnDefinitions>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="3*" />
                                <RowDefinition Height="1*" />
                                <RowDefinition Height="1*" />
                                <RowDefinition Height="1*" />
                                <RowDefinition Height="4*" />
                                <RowDefinition Height="1*" />
                                <RowDefinition Height="1*" />
                                <RowDefinition Height="4*" />
                            </Grid.RowDefinitions>
                            <Border
                                Name="MainBorder"
                                Grid.ColumnSpan="9"
                                Grid.RowSpan="9"
                                CornerRadius="4"
                                BorderThickness="1"
                                Background="Transparent" />
                            <Border
                                Name="InnerBorder"
                                Grid.Column="1"
                                Grid.ColumnSpan="5"
                                Grid.Row="2"
                                Grid.RowSpan="5"
                                BorderThickness="1"
                                BorderBrush="Gray" />
                            <Path
                                Name="InnerPath"
                                Grid.Column="1"
                                Grid.ColumnSpan="5"
                                Grid.Row="2"
                                Grid.RowSpan="5"
                                Data="M31,5 L19.5,5 19.5,19.5 34.5,19.5 34.5,11.75"
                                Stretch="Fill"
                                Stroke="Gray"/>
                            <Path
                                Name="CheckMark"
                                Grid.Column="2"
                                Grid.ColumnSpan="5"
                                Grid.Row="1"
                                Grid.RowSpan="5"
                                Opacity="0"
                                Data="M9.07743946676476E-09,4.31805768640244L4.68740335877841,8.86361158398516C4.68740335877841,8.86361158398516,16.3281249985376,-2.42451336648723,16.3281249985376,-2.42451336648723L14.0622100581796,-4.77304938341948 4.68740335877846,4.31805791992662 2.22656251699567,1.93164208562579z"
                                Fill="Orange"
                                Stretch="Fill"
                                Stroke="Orange" />
                            <Path
                                Name="InderminateMark"
                                Grid.Column="3"
                                Grid.Row="4"
                                Data="M0,4 L1,5 5,1 4,0"
                                Opacity="0"
                                Stretch="Fill"
                                StrokeThickness="0"
                                Fill="#808080" />
                        </Grid>
                    </BulletDecorator.Bullet>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CheckStates">
                            <VisualState x:Name="Checked">
                                <Storyboard>
                                    <DoubleAnimation Storyboard.TargetProperty="Opacity"
                                         Storyboard.TargetName="CheckMark" Duration="0:0:0.2" To="1" />
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Unchecked" >
                                <Storyboard>
                                    <DoubleAnimation Storyboard.TargetProperty="Opacity"
                                         Storyboard.TargetName="CheckMark" Duration="0:0:0.2" To="0" />
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Indeterminate">
                                <Storyboard>
                                    <DoubleAnimation Storyboard.TargetProperty="Opacity"
                                         Storyboard.TargetName="InderminateMark" Duration="0:0:0.2" To="1" />
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <ContentPresenter 
                            Margin="4,0,4,0"
                            VerticalAlignment="Center"
                            HorizontalAlignment="Left"
                            RecognizesAccessKey="True" />
                </BulletDecorator>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="InnerBorder" Property="BorderBrush" Value="#FF7AA0CD" />
                        <Setter TargetName="InnerPath" Property="Stroke" Value="#FF7AA0CD" />
                        <Setter TargetName="CheckMark" Property="Fill" Value="Gainsboro"/>
                        <Setter TargetName="CheckMark" Property="Stroke" Value="Gainsboro"/>
                    </Trigger>
                    <Trigger Property="IsChecked" Value="True">
                        <Setter TargetName="InnerBorder" Property="Visibility" Value="Collapsed" />
                        <Setter Property="Foreground" Value="#303030"/>
                    </Trigger>
                    <Trigger Property="IsChecked" Value="False">
                        <Setter TargetName="InnerBorder" Property="Visibility" Value="Collapsed" />                            
                    </Trigger>
                    <Trigger Property="IsPressed" Value="True">
                        <Setter TargetName="MainBorder" Property="Background" Value="#81d2eb" />
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="True">
                        <Setter Property="Foreground" Value="Gainsboro"/>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="False">
                        <Setter Property="Foreground" Value="#55B3B3B6"/>
                        <Setter TargetName="CheckMark" Property="Fill" Value="Orange" />
                        <Setter TargetName="CheckMark" Property="Stroke" Value="Orange" />
                        <Setter TargetName="InnerPath" Property="Stroke" Value="#55649EB4" />
                        <Setter TargetName="InderminateMark" Property="Fill" Value="#cccccc" />
                        <Setter TargetName="InnerBorder" Property="BorderBrush" Value="#55649EB4" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

So i try to add very simple style for Foreground Color when my Checkbox is checked:

<Trigger Property="IsChecked" Value="True">
    <Setter TargetName="InnerBorder" Property="Visibility" Value="Collapsed" />
    <Setter Property="Foreground" Value="#303030"/>
</Trigger>

And for some reason this is not working and Foreground color not changing. Any suggestion why ?