If you want to link the Joomla template css to your JCE editor follow these steps:
From the Joomla Admin backend goto:
Components --> JCE Administration --> ConfigurationScroll down to formatting set "use template CSS: to NO put the path of your template CSS file into the "use Custom CSS" field ie [templates/your_template_name/css/template_css.css]
Now you've got a big long list of styles you'll probly never use, so cut and paste the ones you want into a simple css file (simple.css) and point the custom CSS field to it:
[templates/your_template_name/css/simple.css]This e-mail address is being protected from spambots. You need JavaScript enabled to view it.