Use graphic style libraries
Graphic style libraries are
collections of preset graphic styles. When you open a graphic style
library, it appears in a new panel (not the Graphic Styles panel).
You select, sort, and view items in a graphic style library the
same as you do in the Graphic Styles panel. However, you can’t add
items to, delete items from, or edit the items in graphic style
libraries.
Open a graphic style library
Select a library from the Window >
Graphic Style Libraries submenu or the Open Graphic Style Library
submenu in the Graphic Styles panel menu.

To automatically open a library when you start
Illustrator, choose Persistent from the library’s panel menu.
Create a graphic style library
Add
the graphic styles you want to the Graphic Styles panel, and delete
any graphic styles you don’t want.

To select
all graphic styles that aren’t used in a document, choose Select
All Unused from the Graphic Styles panel menu.
Choose Save Graphic Style Library from the Graphic Styles
panel menu.
You can save the library anywhere. However, if
you save the library file in the default location, the library name
will appear in the User Defined submenu of teh Graphic Style Libraries
and Open Graphic Style Library menu.
Move graphic styles from a library to the Graphic Styles panel
Drag one or more graphic styles from the graphic
styles library to the Graphic Styles panel.
Select the graphic styles you want to add, and select Add
To Graphic Styles from the library’s panel menu.
Apply a graphic style to an object in the document. The graphic
style is automatically added to the Graphic Styles panel.