The gatein-resources.xml needs to specify the new portal skin. This includes specifying the name of the new skin, where to locate its CSS stylesheet file and whether to overwrite an existing portal theme with the same name.

<gatein-resources>

  <portal-skin>

    <skin-name>MySkin</skin-name>

    <css-path>/skin/myskin.css</css-path>

    <overwrite>false</overwrite>

  </portal-skin>

</gatein-resources>

      

The default portal skin and window styles are defined in 01eXoResources.war/WEB-INF/gatein-resources.xml.