How can I change a datagrids row background colour when date is less than todays

public class CellDateColorConverter : IMultiValueConverter
    {

        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (values[0] is DateTime && values[1] is DateTime)
            {

                DateTime Jobdate = (DateTime)values[0];
                DateTime DateToday = (DateTime)values[1];

                if (Jobdate.Date < DateToday.Date)
                {
                    return Color.Red;
                }
            }

            return System.Windows.Data.Binding.DoNothing;
    }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotSupportedException("CellDateColorConverter is a OneWay converter.");
        }
    }

<DataGrid xmlns:System="clr-namespace:System;assembly=mscorlib"  Cursor="Hand" BorderBrush="#fbfbfb" BorderThickness="1" SelectionUnit="FullRow" IsTextSearchEnabled="True" IsTextSearchCaseSensitive="False" IsReadOnly="True" ScrollViewer.HorizontalScrollBarVisibility="Auto" ScrollViewer.VerticalScrollBarVisibility="Auto" Width="693" Height="520" x:Name="tblunallocatedjobs" ItemsSource="{Binding Path=tblunallocatedjobs}" AutoGenerateColumns="False" Margin="0,20,0,0" MouseDoubleClick="tblunallocatedjobs_MouseDoubleClick" Background="#fbfbfb">
                            <DataGrid.Resources>
                                <local:CellDateColorConverter x:Key="CellDateColorConverter"/>
                            </DataGrid.Resources>
                            <DataGrid.RowStyle>
                                <Style TargetType="{x:Type DataGridRow}">
                                    <Setter Property="Height" Value="40"></Setter>
                                    <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
                                    <Style.Triggers>
                                        <DataTrigger Binding="{Binding JobDate.Date}" Value="{x:Static System:DateTime.Today}">
                                            <Setter Property="Background" Value="#00ce3f"/>
                                        </DataTrigger>
                                    </Style.Triggers>
                                </Style>
                            </DataGrid.RowStyle>
                            <DataGrid.Columns>
                                <DataGridTextColumn Header="Job Number" Binding="{Binding ID}"/>
                                <DataGridTextColumn Header="Booked By" Binding="{Binding UserName}"/>
                                <DataGridTextColumn Header="Job" Binding="{Binding JobType}"/>
                                <DataGridTextColumn Header="Date" Binding="{Binding Path=JobDate, StringFormat=\{0:dd/MM/yyyy\}}" x:Name="JobDate">
                                    <DataGridTextColumn.ElementStyle>
                                        <Style TargetType="TextBlock">
                                            <Setter Property="Background">
                                                <Setter.Value>
                                                    <MultiBinding Converter="{StaticResource CellDateColorConverter}">
                                                        <Binding Path="JobDate"/>
                                                        <Binding Path="DateToday"/>
                                                    </MultiBinding>
                                                </Setter.Value>
                                            </Setter>
                                        </Style>
                                    </DataGridTextColumn.ElementStyle>
                                </DataGridTextColumn>
                                <DataGridTextColumn Header="Todays Date" Binding="{Binding Path=DateToday, StringFormat=\{0:dd/MM/yyyy\}}" x:Name="DateToday">
                                    <DataGridTextColumn.ElementStyle>
                                        <Style TargetType="TextBlock">
                                            <Setter Property="Background">
                                                <Setter.Value>
                                                    <MultiBinding Converter="{StaticResource CellDateColorConverter}">
                                                        <Binding Path="JobDate"/>
                                                        <Binding Path="DateToday"/>
                                                    </MultiBinding>
                                                </Setter.Value>
                                            </Setter>
                                        </Style>
                                    </DataGridTextColumn.ElementStyle>
                                </DataGridTextColumn>
                                <DataGridTextColumn Header="Start Time" Binding="{Binding JobTimeStart}"/>
                                <DataGridTextColumn Header="Finish Time" Binding="{Binding JobTimeFinish}" x:Name="JobTimeFinish"/>
                                <DataGridTextColumn Header="Post Code" Binding="{Binding PostCode}"/>
                                <DataGridTextColumn Header="Price" Binding="{Binding JobPrice}"/>
                                <DataGridTextColumn Header="Job Status" Binding="{Binding Allocation}"/>
                            </DataGrid.Columns>
                        </DataGrid>

private void GetUnallocatedJobs()
       {
           using (SqlConnection conn = new SqlConnection(connectionString))
           {
               conn.Open();
               string query_search = "SELECT * FROM tblJobs WHERE (ID LIKE @ID OR PostCode LIKE @PostCode) AND Allocation='Unallocated' AND JobStatus != 'Cancelled' AND JobDate < @CurrentDate ORDER BY JobDate DESC, PostCode";
               SqlCommand cmd = new SqlCommand(query_search, conn);

               cmd.Parameters.AddWithValue("@CurrentDate", DateTime.Now);
               cmd.Parameters.AddWithValue("@ID", "%" + Search.Text + "%");
               cmd.Parameters.AddWithValue("@PostCode", "%" + Search.Text + "%");

               using (SqlDataAdapter adapter = new SqlDataAdapter(cmd))
               {
                   DataTable dt = new DataTable();

                   dt.Columns.Add("DateToday");
                   DataRow _ravi = dt.NewRow();
                   _ravi["DateToday"] = DateTime.Now.ToString("dd/MM/yyyy");
                   dt.Rows.Add(_ravi);



                   adapter.Fill(dt);

                   tblunallocatedjobs.ItemsSource = dt.DefaultView;
               }
               sqlCon.Close();


           }
       }