What is the use of styles directory present inside global and local domains

Hi,

Recently we encountered an issue w.r.t a business user who was not able to see one of the key workbook for forecast approval whereas the other users were able to see the workbook.

Later on Oracle recommended to delete style from the local domain for the user and that resolved the issue.

In the configuration guide we see that styles are used to highlight, font color, text etc and then can be assigned to measure and workbook tools. My question is that are these styles also user specific and how they are related to the user?