Set the background color of datagridcell control in WPF?

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C#

WPF

In my project i have a datagridcell control which i want to change its background value when the client click it. the DataGridCell style is inherit from a Resource Dictionary.
The problem is, the background doesn't change at all.
At first i thought maybe my trigger event is wrong, but event when i set the background directly on the control and remove the style, the background stays Transparent.
Here is the declaration of the control:

<Grid Style="{DynamicResource GridBrushColorByTheme}">
        <WrapPanel>
            <DataGridCell Content="1" Style="{DynamicResource cellStyle}"/>
        </WrapPanel>
    </Grid>

And here is the style (Please look at the "Click Style" in the buttom of the style):

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
                    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
                    mc:Ignorable="d">
    <Style x:Key="cellStyle" TargetType="{x:Type DataGridCell}">
        <Setter Property="Padding" Value="0" />
        <Setter Property="Margin" Value="10,10,0,0" />
        <Setter Property="VerticalContentAlignment" Value="Center"/>
        <Setter Property="HorizontalContentAlignment" Value="Center"/>
        <Setter Property="HorizontalAlignment" Value="Center"/>
        <Setter Property="VerticalAlignment" Value="Center"/>
        <Setter Property="Background" Value="Transparent" />
        <Setter Property="TextBlock.TextAlignment" Value="Center"/>
        <Setter Property="FontSize" Value="20"/>
        <Setter Property="Width" Value="100"/>
        <Setter Property="Height" Value="36"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="DataGridCell">
                    <Border>
                        <Border x:Name="border"
                              BorderBrush="Transparent"
                              BorderThickness="0"
                              Padding="3"
                              CornerRadius="0">
                            <ContentPresenter />
                        </Border>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <!--Steady Foreground-->
            <DataTrigger Binding="{Binding Source={StaticResource odpSettings},Path=Theme, Mode=OneWay}" 
                         Value="Dark">
                <Setter Property="Foreground"  Value="{DynamicResource DarkThemeForegroundColor(White)}"/>
            </DataTrigger>
            <DataTrigger Binding="{Binding Source={StaticResource odpSettings},Path=Theme, Mode=OneWay}" 
                         Value="Light">
                <Setter Property="Foreground"  Value="{DynamicResource LightThemeForegroundColor(Black)}"/>
            </DataTrigger>
            <!--Hover Style - Drak!-->
            <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsMouseOver}" Value="True"/>
                    <Condition Binding="{Binding Source={StaticResource odpSettings},Path=Theme, Mode=OneWay}" Value="Dark"/>
                </MultiDataTrigger.Conditions>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type DataGridCell}">
                            <Border BorderBrush="{DynamicResource LightThemeBgColor}" Background="{DynamicResource LightThemeBgColor}" CornerRadius="5">
                                <TextBlock Padding="3" Text="{TemplateBinding Content}" TextAlignment="Center">
                                    <TextBlock.Triggers>
                                        <EventTrigger RoutedEvent="TextBlock.Loaded">
                                            <BeginStoryboard>
                                                <Storyboard>
                                                    <DoubleAnimation
                                                            Storyboard.TargetName="{x:Null}" 
                                                            Storyboard.TargetProperty="(TextBlock.Opacity)"
                                                            From="1.0" To="0.0" Duration="0:0:0.7" 
                                                            AutoReverse="True" RepeatBehavior="Forever" />
                                                </Storyboard>
                                            </BeginStoryboard>
                                        </EventTrigger>
                                    </TextBlock.Triggers>
                                </TextBlock>
                            </Border>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
                <Setter Property="Foreground"  Value="{DynamicResource LightThemeForegroundColor(Black)}"/>
            </MultiDataTrigger>
            Hover Style - Light!
            <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsMouseOver}" Value="True"/>
                    <Condition Binding="{Binding Source={StaticResource odpSettings},Path=Theme, Mode=OneWay}" Value="Light"/>
                </MultiDataTrigger.Conditions>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type DataGridCell}">
                            <Border BorderBrush="{DynamicResource DarkThemeBgColor}" Background="{DynamicResource DarkThemeBgColor}" CornerRadius="5">
                                <TextBlock Padding="3" Text="{TemplateBinding Content}" TextAlignment="Center" >
                                    <TextBlock.Triggers>
                                        <EventTrigger RoutedEvent="TextBlock.Loaded">
                                            <BeginStoryboard>
                                                <Storyboard>
                                                    <DoubleAnimation
                                                            Storyboard.TargetName="{x:Null}" 
                                                            Storyboard.TargetProperty="(TextBlock.Opacity)"
                                                            From="1.0" To="0.0" Duration="0:0:0.7" 
                                                            AutoReverse="True" RepeatBehavior="Forever" />
                                                </Storyboard>
                                            </BeginStoryboard>
                                        </EventTrigger>
                                    </TextBlock.Triggers>
                                </TextBlock>
                            </Border>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
                <Setter Property="Foreground"  Value="{DynamicResource DarkThemeForegroundColor(White)}"/>
            </MultiDataTrigger>
            <!--Click Style!-->
            <Trigger Property="DataGridCell.IsSelected" Value="True">
                <Setter Property="Background" Value="{DynamicResource OrangeThemeBgColor}"/>
                <Setter Property="BorderBrush" Value="{DynamicResource OrangeThemeBgColor}"/>
            </Trigger>
        </Style.Triggers>
    </Style>
</ResourceDictionary>

Can anyone please help me? how am i suppouse to set the background when clicking the cell?
Thanks, oron!

What I have tried:

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