Adminer
From Amahi Wiki
Adminer has the ability to install different themes, and here is how.
You can find different skins at http://www.adminer.org/en/#extras .
The best way to do this is to do it by command line (or terminal). So get on your HDA or better yet, SSH in and login.
You must be root to wget a file, so login as root, do:
su -
Enter your root password.
Now navigate to the directory where Adminer is located:
cd /var/hda/web-apps/adminer/html
After that, you will need to copy the download link to the theme you would like to use, im just using Hever as an example:
wget http://www.adminer.org/static/designs/hever/adminer.css
Then go to http://adminer (or refresh the page if your already there) and you should see your new theme.