A theme is a collection of styles that can specify the colors used in a report, the font used for different text, label, or data items, the spacing or alignment of items, border styles, and so on. Designers create a theme to apply a consistent style or appearance to a report.

When you create a template, consider creating different themes, so that the user can choose from multiple styles. The creation of a theme is optional. Themes are stored in a BIRT library file, separate from the template file.

Defining all the styles in a theme within a library makes it easier to maintain and update the appearance of a template. When a user requests new or modified styles to use with a particular template, update the theme in the library, then publish the latest version of the library to the server. You do not need to modify the template file each time.