Custom fivestar widget does not display custom icons
Without seeing your file structure it is difficult to discern your problem.  But I suspect the hook is having issues with the path to your css.  I have found a really nice tutorial to do this, it setups a widgets folder in your custom module and uses file_scan_directory to scan all custom star folders in that folder.

https://www.drupal.org/node/234391

Be mindful that there is a slight error in the code as it is outdated, in the foreach, you need to use $file->uri instead of $file->filename for the array key.




foreach ($files as $file) {
    if (strpos($file->filename, '-rtl.css') === FALSE) {
      $widgets[$file->uri] = drupal_ucfirst($file->name);
    }
  }