I am able to access styles that appear in the system styles folders, such as ArcGIS 2D. The code looks like this:
var arcgis_2d = ArcGIS.Desktop.Core.Project.Current.GetItems<StyleProjectItem>().First(si => si.Name == "ArcGIS 2D"); <SPAN class="line-numbers-rows"><SPAN></SPAN></SPAN>
But that code does not allow me to get to styles in the Favorites folder:

How would I access styles in the Favorites folder? Thanks.