The sample project illustrates customziation of the Pane templates, and in particular the button chrome control which is part of the tabs. That is why the tabs do appear customized in your screenshot.
The rest of the cases, however, are related to customizing the pane group header or the ToolWindow, and not the tabs. In cases 3, 5, 6 you need to customize the style for the RadPaneGroup and relevant brushes for its visual states. In case 2, what you need to customize is the ToolWindow
rather than the pane tempalte.
All these styles are accessible to be generated from Expression Blend. Please, use them to make your background customizations.
I hope this will be helpful.
the Telerik team
Explore the entire Telerik portfolio by downloading the Ultimate Collection trial package. Get it now >>