Adding new styles to HTML editor

Similar to @alanstanley’s post on adding plugins, is there a way to add local styles to the CKEditor but without editing core code? I’ve tried the blunt approach of adding a new asset/vendor/ckeditor/styles.js file with new styles only to my theme, but nothing happens in my admin interface from merely adding the file. Something happens when I add an appendFile to layout.phtml, but that something is a white screen of death.