When you delete a style, all pages and regions that used the style revert to the page group default style, or the system default style if there is no page group default style.
You
must have at least one of the following privileges to delete a style:
Manage All privileges on the page group to which the style belongs
Manage Style privileges on the page group
Manage Style global privileges on All Page Groups
You cannot delete the system default style.
In the Navigator click Delete next to the style that you want to delete.
Tip: If the style is used by more than one page group, it will be under the Shared Objects page group.
In the confirmation page, click Yes.