string packUri = String.Format(@"/WpfControlLibrary1;component/Dictionary1.xaml");

            ResourceDictionary rd = Application.LoadComponent(new Uri(packUri, UriKind.Relative)) as ResourceDictionary;

            this.Resources.MergedDictionaries.Clear();

            this.Resources.MergedDictionaries.Add(rd);
            //Application.Current.Resources.MergedDictionaries.Clear();
            //Application.Current.Resources.MergedDictionaries.Add(rd);

 <ResourceDictionary Source="/PresentationFramework.Royale;V3.0.0.0;31bf3856ad364e35;component\themes\royale.normalcolor.xaml" />