Overrides won't work well neither for the html templates (_sub_header.html -> logo placement change) nor for css (common.css -> body color override)
Where were all the good days were we had *.tpl's to work with and everything was so easier!?
Seems you have enabled cache for template and css files - in this case you should clear files from cache and chace_pulbic directories for working your changes.
Where were all the good days were we had *.tpl's to work with and everything was so easier!?