Basically, a theme is a folder that sits inside the themes
folder in your PHP-Nuke installation. Different themes correspond to different folders in the themes
folder, and adding or removing a theme is as straightforward as adding or removing the relevant folder from the themes
folder.
By default, you will find around 14 themes in a standard PHP-Nuke installation. DeepBlue is the default theme.
Themes can be chosen in one of two ways:
By the administrator: You can simply select the required theme from the General Site Info panel of the Site Preferences administration menu and save the changes. The theme selected by the administrator is the default theme for the site and will be seen by all users of the site, registered or unregistered.
By the user: Users can override the default theme set by the administrator from the Themes option of the Your Account module. This sets a new, personal, theme that will be displayed to that user. Note that this isn't a theme especially customized...