WPF Create Visual Style

CreateStyle.cs

private Style GetDarkStyleProgrammatically()
{
    var fef = new FrameworkElementFactory(typeof(Rectangle));
    fef.SetValue(Rectangle.StrokeThicknessProperty, 3.0);
    fef.SetValue(Rectangle.StrokeProperty, new BrushConverter().ConvertFrom("#00008b"));
    fef.SetValue(Rectangle.SnapsToDevicePixelsProperty, true);
    var template = new ControlTemplate { VisualTree = fef };

    var setter = new Setter(Control.TemplateProperty, template);

    var style = new Style(typeof(IFrameworkInputElement));
    style.Setters.Add(setter);

    return style;
}

private Style GetDarkStyleFromXaml()
{
  var xaml = "<ControlTemplate><Rectangle StrokeThickness=\"3\" Stroke=\"Blue\" SnapsToDevicePixels=\"true\"/></ControlTemplate>";
  MemoryStream sr = new MemoryStream(Encoding.ASCII.GetBytes(xaml));
  ParserContext pc = new ParserContext();
  pc.XmlnsDictionary.Add("", "http://schemas.microsoft.com/winfx/2006/xaml/presentation");
  pc.XmlnsDictionary.Add("x", "http://schemas.microsoft.com/winfx/2006/xaml");
  var  template = (ControlTemplate)XamlReader.Load(sr, pc);

    var setter = new Setter(Control.TemplateProperty, template);

    var style = new Style(typeof(IFrameworkInputElement));
    style.Setters.Add(setter);

    return style;
}