You have several options when setting up a new site on Pantheon which are listed below.
Pantheon Upstreams: WordPress/Drupal
You can use a default installations of WordPress or Drupal on Pantheon by following the Pantheon instructions. Using this option is “as is” and you will need a developer to set up and maintain your site and it’s components, themes, and plugins.
USC Gateway Upstream
USC has developed the USC Gateway Upstream that incorporates USC Branding and Identity with many features. This option is managed by USC Information Technology Services (ITS)
USC Communications Site
USC Communications has developed a theme that incorporates USC Branding and Identity with various features. This theme is used for the USC Homepage and you can inquire about using it for your USC approved School or Department.