public static class ApplicationOptions 

var lastToolActive = ApplicationOptions.LayoutOptions.KeepLastToolActive;
var warnOnSurrounds = ApplicationOptions.LayoutOptions.WarnAboutAssociatedSurrounds;
//eg <Install_Path>\Resources\LayoutTemplates\en-US
var gallery_path = ApplicationOptions.LayoutOptions.LayoutTemplatePath;
var defaultGuideColor = ApplicationOptions.LayoutOptions.DefaultGuideColor;
QueuedTask.Run(() =>
{
  var guideColor = ApplicationOptions.LayoutOptions.GetGuideColor();
});

//keep graphic element insert tool active
ApplicationOptions.LayoutOptions.KeepLastToolActive = true;
//no warning when deleting a map frame results in other elements being deleted
ApplicationOptions.LayoutOptions.WarnAboutAssociatedSurrounds = false;
//path to .pagx files used as templates
ApplicationOptions.LayoutOptions.LayoutTemplatePath = @"D:\data\layout_templates";

QueuedTask.Run(() =>
{
  var guideColor = ApplicationOptions.LayoutOptions.GetGuideColor();
  // set guide color
  ApplicationOptions.LayoutOptions.SetGuideColor(ColorFactory.Instance.RedRGB);
});

//Note: see also SymbolFactory.Instance.GetAvailableFonts() which returns the
//same list. Use for TextAndGraphicsElementsOptions.GetAvailableFonts() convenience

QueuedTask.Run(() =>
{
  //A list of tuples of Font name + associated Font Styles, one tuple per
  //font, is returned
  var fonts = ApplicationOptions.TextAndGraphicsElementsOptions.GetAvailableFonts();
  StringBuilder sb = new StringBuilder();
  sb.AppendLine("Pro Fonts\r\n============================");
  foreach (var font in fonts)
  {
    var styles = string.Join(",", font.fontStyles);
    sb.AppendLine($"{font.fontName}, [{styles}]");
  }
  System.Diagnostics.Debug.WriteLine(sb.ToString());
});

QueuedTask.Run(() =>
{
  //Get the default font (see also 'SymbolFactory.Instance.DefaultFont')
  var def_font = ApplicationOptions.TextAndGraphicsElementsOptions.GetDefaultFont();
  System.Diagnostics.Debug.WriteLine(
    $"\r\ndefault font: {def_font.fontName}, {def_font.styleName}");

  //Get the default graphics element symbols - point, line, poly, text
  var ptSymbol = ApplicationOptions.TextAndGraphicsElementsOptions.GetDefaultPointSymbol();
  var lineSymbol = ApplicationOptions.TextAndGraphicsElementsOptions.GetDefaultLineSymbol();
  var polySymbol = ApplicationOptions.TextAndGraphicsElementsOptions.GetDefaultPolygonSymbol();
  var textSymbol = ApplicationOptions.TextAndGraphicsElementsOptions.GetDefaultTextSymbol();
});

QueuedTask.Run(() =>
{
  //Set a default font. Use its default style
  ApplicationOptions.TextAndGraphicsElementsOptions.SetDefaultFont("tahoma");
  //or specify an explicit style
  ApplicationOptions.TextAndGraphicsElementsOptions.SetDefaultFont("tahoma", "bold");

  //Create symbols
  var ptSymbol2 = SymbolFactory.Instance.ConstructPointSymbol(
    ColorFactory.Instance.RedRGB, 14, SimpleMarkerStyle.Diamond);
  var lineSymbol2 = SymbolFactory.Instance.ConstructLineSymbol(
    ColorFactory.Instance.RedRGB, 2, SimpleLineStyle.Dash);
  var polySymbol2 = SymbolFactory.Instance.ConstructPolygonSymbol(
    ColorFactory.Instance.RedRGB, SimpleFillStyle.DiagonalCross);
  var textSymbol2 = SymbolFactory.Instance.ConstructTextSymbol(
    ColorFactory.Instance.RedRGB, 12);

  //Set default point, line, poly, text graphics element symbols
  ApplicationOptions.TextAndGraphicsElementsOptions.SetDefaultPointSymbol(ptSymbol2);
  ApplicationOptions.TextAndGraphicsElementsOptions.SetDefaultLineSymbol(lineSymbol2);
  ApplicationOptions.TextAndGraphicsElementsOptions.SetDefaultPolygonSymbol(polySymbol2);
  ApplicationOptions.TextAndGraphicsElementsOptions.SetDefaultTextSymbol(textSymbol2);
});