https://docs.devexpress.com/WPF/400728/common-concepts/themes/palettes#predefined-palettes
ThemeManager.PreloadThemeResourceAsync("Office2019White", runTypeInitializers: false).Wait();
ControlzEx.Theming.ThemeManager.Current.AddLibraryTheme(new ControlzEx.Theming.LibraryTheme(
new Uri("pack://application:,,,/Resources/ColorScheme.xaml"),
ControlzEx.Theming.ThemeManager.Current.ChangeTheme(Current, colorScheme);
Theme.RegisterPredefinedPaletteThemes();
string paletteName = "Light.Blue";
ApplicationThemeHelper.ApplicationThemeName = paletteName + Theme.Office2019White.Name;