You can use the theme concept to change the appearance of one or more BSP applications after they have been created.

A theme is created as an independent development object in the Web Application Builder. A theme can be assigned to BSP applications in order to redefine style sheets and MIMEs in the pages of a BSP application after they have been created. The theme concept is a powerful tool for easily changing the layout of your pages in accordance with your needs, without the need for modifying the layout source code.