The C1TreeView control contains five built-in themes. When one of these themes is selected, all other ASP.NET Web Forms studio controls on the page will be skinned accordingly. The themes will appear on the C1TreeView control as follows:

 

Aristo
Cobalt
Midnight
Rocket
Sterling

To set the theme of the C1TreeView control, simply set its Theme property to one of the built-in themes.