The appearance of the CMSTabControl control is determined by the CSS classes it uses and by some of its properties.

 

It uses the same CSS classes as the BasicTabControl, which it inherits. These can be found at BasicTabControl -> Appearance and styling.

 

The recommended place to define these classes is in a stylesheet in the Kentico CMS administration interface at Site Manager -> Development -> CSS stylesheets. These stylesheets can be applied to individual documents (pages) that contain the control in CMS Desk -> Content -> Edit -> Properties -> General -> CSS stylesheet.