I would like to be able to set different sections of my website in different colors, but using the same template (i.e. Firenzie). How can this be accomplished?
Yes you can by many means. One simple way is creating a lean copy of Firenzie, which means a clone it and name it rt_firenzie_s1 for style 1 then s2 and so on; make sure you change the default style in the index.php. What I mean with a lean copy is by removing all the other style from you clone leaving the style you have selected to just install the used style and related files.
Then install all the new style and assign them to a section in your site from the Template Manager. There was a post similar this
here
but different template.
With Firenzie I think you can rename just rename it then update the name in the templateDetails.xml file. To be sure I will check the index.php, template_css.css and the xml file. If you are concern about copyrights there was a post about this
here
for you to consider.
Templates are not the same so make sure to check the hardcoded template names and folder.