Just for fun, I wanted to install the “Metro” theme for phpMyAdmin on my QNAP TS-453mini. It’s not automatic from the Web interface but it can be done via the shared folders.
Once phpMyAdmin is installed from the “App Center”, open the “Shared Folders” from the “Control Panel”. Locate the “Web” folder and click the “Edit Shared Folder Permission”. In my case, my normal user was not allowed to access it, so I switched to “Read/Write” permissions.
Now, download the Metro archive, from https://www.phpmyadmin.net/themes/. From the “File Station”, browse to the “Web/phpMyAdmin/themes” directory and click the “Upload File” button. Select the “metro-2.5.zip” file, click the “More Action” button and select “Extract / Extract here”. Once the extraction is finished, return to phpMyAdmin.
In the phpMyAdmin homepage, from the “Appearance Settings”, select the “Metro” theme. Et voilà!