Apologies in advance if this is not the proper forum for this question; please direct me elsewhere if this is the case.

I have been tasked with updating the theme of our ZCS 8.0.0 instance. I have been following the instructions from the manual :

  1. In the Zimbra Administration web interface, I have navigated to Domains > [our domain] > Themes
  2. I have changed the foreground, background, secondary and selection colors and Saved
  3. I have also changed the Application Logo banner URL to a custom image
  4. When prompted, I have flushed the theme cache

However, none of the changes are displayed.

The documentation is unclear; the system gives an opportunity to change the colors of the 4 items above - but what theme are these changes being applied to? All of them? The end user currently has a choice between 18 themes (Bare, Beach, Bones, etc) - what exactly do the color changes I make in the Zimbra Administration interface for our domain change, and how do I see my changes?