There is a problem with css class "label" in CiviCase. This affects the CiviCase dashboard and custom fields in the Case view panel. I think this only affects the Joomla version of CiviCRM 4.7.14.
This problem was fixed in version 4.7.16. More details here. If for some reason you need a quick fix for version 4.7.14, comment out the last 10 lines of css/joomla.css.