If you're doing it through the templates, I'm not sure you can alter these independently. You can alter all of the folders format together, by altering the code between the

<%loop folders_list%><%endloop%>

tags. I guess you could also do a <%if foldername = 'inbox'%> do this <%endif%> to specify a different look for that folder. I'm not sure what the tag is for the folder name or title, whether it's 'foldername' or something else? Perhaps one of the GT guys could comment on this, and if it would work.

Hope that helps,
Regan.