If you have access to the root, we copied the skins and container folder, modified the stock DNNgray skin to a custom one to match our school site that is built with a different application, I but remember that is you modify the htm files that you do the ascx files as well, but be sure to pay attention to coding, this was not hard I just had to nose around and trial an error, now back up ur skins folder or make a new one copy the default one over and then modify then oyu can go into and select the custom them from your Skins interface......for the skin and the container....if you know what the gray skin looks like look how I changed it to what you seeo n our tech site, also ,I made a transparent logo, and used the tables to make my header back ground and moving the [logo] and other server side things around moved placements.....but be sure to change in the ascx file  if they sta on the site......  http://it.bentonschools.org the parent site is http://www.bentonschools.org  hope this helps let me know if you need any pointers alot of smart people on here, I am new to DNN but like it.....