What do the red/green bars next to Folios names mean?

While in the Folios view in the builder, you will see red and green bars next to StickyFolios names, which indicate the published status of each StickyFolio in the account.  

Green - Shows your Folio has been Published and there are no Unpublished changes.

Red - Indicates that your Folio has Unpublished changes or that the site has not yet been Published.

How can I tell if my Folio was publised previously if it's set to red?

Never Published (1) - If the Last Published column shows Never, then the Folio has not yet been published.

Unpublished changes (2)- If the Last Published column shows a date, then the Folio has been published, but recent changes/updates have not been Published.