为CustomGrid设置背景单元格颜色的简单方法是什么?

I've got:

我有:

<CustomControl:GridControl ShowCustomGridLines="True" Grid.Column="2" Grid.Row="0">
            <Grid.ColumnDefinitions>
                <ColumnDefinition />
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition />
                <RowDefinition />
            </Grid.RowDefinitions>
        <TextBlock Grid.Column="0" Grid.ColumnSpan="3" Grid.Row="0" HorizontalAlignment="Center" VerticalAlignment="Center" Name="txbCaption" Text="{Binding Caption}" />
            <CustomControl:GridControl ShowCustomGridLines="True" Grid.Column="2" Grid.Row="1">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition />
                    <ColumnDefinition />
                    <ColumnDefinition />
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition />
                </Grid.RowDefinitions>
                <TextBlock Grid.Column="0" Grid.Row="1" Text="П" HorizontalAlignment="Center" VerticalAlignment="Center" />
                <TextBlock Grid.Column="1" Grid.Row="1" Text="Ф" HorizontalAlignment="Center" VerticalAlignment="Center" Background="Yellow" />
                <TextBlock Grid.Column="2" Grid.Row="1" Text="%" HorizontalAlignment="Center" VerticalAlignment="Center" />
            </CustomControl:GridControl>
<CustomControl:GridControl Sh