Binding the Label Foreground Color to a property in View Model WPF

namespace MyNamespace
{
  using System;
  using System.Globalization;
  using System.Windows.Data;
  using System.Windows.Media;

  /// <summary>
  /// Converter to determine whether or not a number is negative, and apply
  /// conditional formatting if it is.
  /// </summary>
  public class NegativeNumberColorConverter : IValueConverter
  {
    #region IValueConverter Members
    /// <summary>
    /// Convert from the value to the colour brush.
    /// </summary>
    /// <param name="value">The value to convert.</param>
    /// <param name="targetType">The parameter is not used.</param>
    /// <param name="parameter">The parameter is not used.</param>
    /// <param name="culture">The parameter is not used.</param>
    /// <returns>The populated colour brush.</returns>
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
      var brush = new SolidColorBrush(Colors.Black);

      if (value == null)
      {
        return brush;
      }

      decimal result;
      var test = decimal.TryParse(value.ToString(), out result);

      if (!test || result >= 0)
      {
        return brush;
      }

      return new SolidColorBrush(Colors.Red);
    }

    /// <summary>
    /// Unused in this implementation.
    /// </summary>
    /// <param name="value">The parameter is not used.</param>
    /// <param name="targetType">The parameter is not used.</param>
    /// <param name="parameter">The parameter is not used.</param>
    /// <param name="culture">The parameter is not used.</param>
    /// <returns>The parameter is not used.</returns>
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
      throw new NotImplementedException();
    }

    #endregion
  }
}