public SegmentSymbolOptions GetSegmentSymbolOptions()

{
  var options = ApplicationOptions.EditingOptions;

  //var options = ApplicationOptions.EditingOptions;
  await QueuedTask.Run(() =>
  {
    var seg_options = options.GetSegmentSymbolOptions();
    //to convert the options to a symbol use
    //SymbolFactory. Note: this is approximate....sketch isn't using the
    //CIM directly for segments
    var layers = new List<CIMSymbolLayer>();
    var stroke0 = SymbolFactory.Instance.ConstructStroke(seg_options.PrimaryColor,
      seg_options.Width, SimpleLineStyle.Dash);
    layers.Add(stroke0);
    if (seg_options.HasSecondaryColor)
    {
      var stroke1 = SymbolFactory.Instance.ConstructStroke(
        seg_options.SecondaryColor, seg_options.Width, SimpleLineStyle.Solid);
      layers.Add(stroke1);
    }
    //segment symbology only
    var sketch_line = new CIMLineSymbol()
    {
      SymbolLayers = layers.ToArray()
    };
  });
}

{
  var options = ApplicationOptions.EditingOptions;
  //var options = ApplicationOptions.EditingOptions;
  await QueuedTask.Run(() =>
  {
    //change the segment symbol primary color to green and
    //width to 1 pt
    var segSymbol = options.GetSegmentSymbolOptions();
    segSymbol.PrimaryColor = ColorFactory.Instance.GreenRGB;
    segSymbol.Width = 1;

    //Are these valid?
    if (options.CanSetSegmentSymbolOptions(segSymbol))
    {
      //apply them
      options.SetSegmentSymbolOptions(segSymbol);
    }
  });
}