r.a.d.treeview supports skinning - you can change the entire appearance of the treeview by changing a single property - Skin. A skin is essentially a set of line images and Css styles applied to the treeview. Skins are located in the ~/RadControls/TreeView/Skins folder. A skin folder consists of all line-images (TopLine.gif, MiddleLine.gif, etc) and a file named Style.css containing the definitions of Css styles applied to different states of tree-nodes (default, hover, select, etc). You can easily change the Skin applied to the treeview by setting the Skin property, e.g.

// aspx / ascx declaration
<radt:radtreeview runat=�server� Skin=�Classic� � />
<radt:radtreeview runat=�server� Skin=�Round3d/Classic� � />

//code
RadTreeView1.Skin = �Classic�
RadTreeView1.Skin = �Round3d/Classic�