C# - Color Extension-Methods

public static Color? HexToColor(this string hex)
{
  if (hex.IsNullOrEmpty() || !hex.IsHexcode())
    return null;

  int red, green, blue = 0;
  try
  {
    if (hex.Length == 3)
    {
      red = int.Parse(hex.Substring(0, 1), System.Globalization.NumberStyles.AllowHexSpecifier);
      green = int.Parse(hex.Substring(1, 1), System.Globalization.NumberStyles.AllowHexSpecifier);
      blue = int.Parse(hex.Substring(2, 1), System.Globalization.NumberStyles.AllowHexSpecifier);
    }
    else if (hex.Length == 6)
    {
      red = int.Parse(hex.Substring(0, 2), System.Globalization.NumberStyles.AllowHexSpecifier);
      green = int.Parse(hex.Substring(2, 2), System.Globalization.NumberStyles.AllowHexSpecifier);
      blue = int.Parse(hex.Substring(4, 2), System.Globalization.NumberStyles.AllowHexSpecifier);
    }
    else
      return null;
  }
  catch
  {
    return null;
  }

  if (red < 0 || red > 255)
    return null;
  if (green < 0 || green > 255)
    return null;
  if (blue < 0 || blue > 255)
    return null;

  return Color.FromArgb(red, green, blue);
}

public static string ColorToHex(this Color clr)
{
  int red   = clr.R;
  int green = clr.G;
  int blue  = clr.B;

  string colorHex = "#";
  colorHex += String.Format("{0:X02}", red);
  colorHex += String.Format("{0:X02}", green);
  colorHex += String.Format("{0:X02}", blue);
  return colorHex;
}