I can't say for sure, but it appears theme it would probably not work. Theme it depends on being able to search through the page and find .css and color references. If they are included in code it may not work, but it really depends on the exact syntax and code you are using, so it could work as well.
Does Dreamweaver work to edit the pages? Does dreamweaver see the linked .css files? Chances are if Dreamweaver works then theme it will.