This section is intended to give you a broad understanding of the possible ways by which you can change the visual appearance of the RadTreeListView and its elements. There is also comprehensive information about their ControlTemplates. You will need this information if you want to customize their appearance.
To learn how to style WPF RadControls read the common topics about Editing Control Templates and Setting a Theme (Using Implicit Styles). If you are new to the controls, they will give you the basic knowledge about it.
There is also another way to obtain the template of a particular visual element. In the RadControls installation folder on your PC, go to Themes folder (Themes.Implicit in case you're using) and select the theme that you use in your application. Then drill down to find the respective Telerik.Windows.Controls.GridView.xaml file in that directory, like it is demonstrated in the Editing Control Templates topic. From this resource dictionary you can extract any needed resources.
You can modify the look of the RadTreeListView and its elements by either changing some of the resources exposed by the API, or by modifying their ControlTemplates. In the control template, you are allowed to reorder the template parts and to add your own elements. However, when changing the control template you should be careful to include all required parts.
As the RadTreeListView inherits the RadGridView, it uses the same styling mechanism. To learn more about how to style specific parts of the control, take a look at the Styles and Templates topics in the RadGridView's documentation.
As of 2013 Q2 SP we have introduced Lightweight Templates for RadGridView and RadTreeListView. Their main idea is to limit the number of visual elements within the templates in order to speed up the performance of the control. Read more