Well, your best bet is to use Webmaster Mode to see which template is which. Then you can open that template and see what style each item is calling. Since all of your dialog boxes are white, I would keep the 'main' font defaulting to black, and just go in and change anything that is outside of the white boxes. Unless of course you are planning on changing those white boxes to black?
As for permissions, read this thread:
http://forum.x-cart.com/viewtopic.php?t=1237