The Appearance Page under Developers Toolkit is available to Unions who have the Advanced Developers Toolkit.
The Manage Themes Page, which can be seen to the right, shows the UnionCloud standard theme and any other themes that have been added to your site.
What is the unstyled theme?
The unstyled theme allows you total control over how your website looks. It removes all of the default CSS, allowing you to customise it using the Global CSS section.