How to apply cell template to particular column headers

<Window.Resources>
<ResourceDictionary>
<LinearGradientBrush x:Key="RowHeaderBackgroundBrush" StartPoint="0.495298,0" EndPoint="1.4953,0">
<LinearGradientBrush.RelativeTransform>
<TransformGroup>
<SkewTransform CenterX="0.495298" CenterY="0" AngleX="-0.823281" AngleY="0"/>
<RotateTransform CenterX="0.495298" CenterY="0" Angle="90.1791"/>
</TransformGroup>
</LinearGradientBrush.RelativeTransform>
<LinearGradientBrush.GradientStops>
<GradientStop Color="#FFF7FAFC" Offset="0"/>
<GradientStop Color="#FFD4DDE9" Offset="1"/>
</LinearGradientBrush.GradientStops>
</LinearGradientBrush>
<Style x:Key="colStyle" TargetType="{x:Type syncfusion:PivotGridTemplateCell}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type syncfusion:PivotGridTemplateCell}">
<StackPanel Grid.Column="1" Orientation="Horizontal" Background="{StaticResource RowHeaderBackgroundBrush}">
<TextBlock Grid.Column="1" Margin="3,4,2,0" Text="{Binding Path=Text, RelativeSource={RelativeSource TemplatedParent}}" TextWrapping="Wrap" HorizontalAlignment="Center" VerticalAlignment="Center" FontFamily="Calibri" FontSize="12"/>
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="Width" Value="70"/> 
</Style>
</ResourceDictionary>
</Window.Resources>
                <Grid> 
                                <Grid.ColumnDefinitions>
                                                <ColumnDefinition Width="4*"/>
                                                <ColumnDefinition Width="2*"/> 
                                </Grid.ColumnDefinitions>
<syncfusion:PivotGridControl Name="PivotGrid" ShowGrandTotals="True" ShowGroupingBar="False" Grid.Column="0" AllowResizeColumns="True" AllowResizeRows="True">
<syncfusion:PivotGridControl.PivotRows>
                                                                <syncfusion:PivotItem FieldMappingName="Category" FieldHeader="C"/>
<syncfusion:PivotItem FieldMappingName="Name" FieldHeader="N" />
                                                </syncfusion:PivotGridControl.PivotRows>
<syncfusion:PivotGridControl.PivotCalculations>
<syncfusion:PivotComputationInfo FieldName="Value1" FieldHeader="VAL ONE" Format="#,##0" SummaryType="DoubleTotalSum"/>
                                                                <syncfusion:PivotComputationInfo FieldName="Value2" FieldHeader="VAL TWO" Format="#,##0" SummaryType="DoubleTotalSum"/>
                                                </syncfusion:PivotGridControl.PivotCalculations>
                                                <syncfusion:PivotGridControl.PivotFields>
                                                                <syncfusion:PivotItem FieldMappingName="Value3" FieldHeader="VAL THREE"/>
                                                </syncfusion:PivotGridControl.PivotFields>
 
<syncfusion:PivotGridControl.ColumnHeaderCellStyle>
<syncfusion:PivotGridCellStyle Style="{StaticResource colStyle}"/>
</syncfusion:PivotGridControl.ColumnHeaderCellStyle>
 
</syncfusion:PivotGridControl>
</Grid>