How to make multicolor in a single cell of DataGrid based on condition

using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;

namespace WpfApplication3
{
  public class NameAvailableTextBlock : TextBlock
  {
    public string InitialName
    {
      get { return (string)GetValue(InitialNameProperty); }
      set { SetValue(InitialNameProperty, value); }
    }

    // Using a DependencyProperty as the backing store for Name.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty InitialNameProperty =
        DependencyProperty.Register("InitialName", typeof(string), typeof(NameAvailableTextBlock), new PropertyMetadata(string.Empty, NameAvailableChanged));

    public string Available
    {
      get { return (string)GetValue(AvailableProperty); }
      set { SetValue(AvailableProperty, value); }
    }

    // Using a DependencyProperty as the backing store for Available.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty AvailableProperty =
      DependencyProperty.Register("Available", typeof(string), typeof(NameAvailableTextBlock), new PropertyMetadata(string.Empty, NameAvailableChanged));

    private static void NameAvailableChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
      ((NameAvailableTextBlock)d).DoNameAvailableChanged();
    }

    private void DoNameAvailableChanged()
    {
      Inlines.Clear();
      // check for either InitialName or Available == null
      string[] names = InitialName.Split('/');
      string[] avail = Available.Split('/');
      if (names.Length != available.Length)
        return;   // just bail-out until the data is what we want to see
      for (int i = 0; i < names.Length; ++i)
      {
        if (i > 0)
        {
          Inlines.Add(new Run("/"));
        }
        var run = new Run(names[i]);
        Inlines.Add(run);
        if (avail[i].Trim() == "1")
        {
          run.Foreground = Brushes.Red;
        }
      }
    }
  }
}

<Window x:Class="WpfApplication3.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApplication3"
        Title="MainWindow"
        Height="350"
        Width="525">
  <Grid>
    <local:NameAvailableTextBlock Width="400"
                                  Height="200" 
                                  InitialName="{Binding InitialNames}"
                                  Available="{Binding Available}" />
  </Grid>
</Window>

using System.Windows;

namespace WpfApplication3
{
  /// <summary>
  /// Interaction logic for MainWindow.xaml
  /// </summary>
  public partial class MainWindow : Window
  {
    public class DummyDataContext
    {
      public string InitialNames { get { return "YVD/LKL/DDS"; } }
      public string Available { get { return "1/0/1"; } }
    }

    public MainWindow()
    {
      InitializeComponent();
      DataContext = new DummyDataContext();
    }
  }

}