I would like to set a default style for the workbook but setDefaultStyle seems to be missing.
Thanks for your posting.
You are right therefore I have logged this so that it could be added sooner.
This issue has been logged as CELLSJAVA-27404.
You can just use Workbook.getDefaultStyle() to get the default style. After calling this method, you will get the Style object, then you can change Style object properties by its setter methods.