expokingz Just released and I am still checking it out
You can now set your own css for the xtgem forum function
The standard css file is at http://xtgem.com/css/xtforum.css you can copy/paste it or upload it by remote server to your root directory (main filebrowser,)
And then rename it
xtforum_template.css
This will then automatically become your forums css template
More on this later after I have tested it