When you save your swatches as Illustrator swatch libraries, you can retrieve them in the swatches panel library menu under User Defined. Illustrator stores your user swatch libraries on your system. Here’s the directory path where you can find your swatches:
Mac: HD / Users / [User Name] / Library / Application Support / Adobe /
Adobe Illustrator CS6 / en_US / Swatches
PC: C: \ Documents and Settings\[User Name]\Application Data\Adobe\
Adobe IllustratorCS6 Settings\en_US\ Swatches
(The directory path varies depending on the version of Windows in use. Refer to Adobe Help for more information.)
Saving your swatches panel as a library will allow you to access it from any Illustrator file. To save your swatches panel as a library, trash any swatches you don’t want to save and then go to the Libraries button at the bottom of the panel and choose Save Swatches…
On a Mac? Don’t see your Library folder? See my tips post on how to reveal it.
For another helpful tip on creating color palettes in Illustrator, see my post on Eyedropper Color in Illustrator.