I didn't see any on a google search or Ebay. The 2 places I would look would be Ebay - try sending a message to a seller listing a different color (esp. if they seem to have an Ebay store) and asking if they have any or know where to get some.
Another great option is Ravelry. Search for the yarn and then look at the "stashes" tab. It will show you who has the yarn in their stash. Some people label their for sale or trade yarn with a tag, those will be listed first. But even if no one has it for sale, page through and see if anyone has some in their stash. They may be willing to sell or trade even if they don't explicitly say so.
The only thing that may be limiting in the Ravelry thing is that a lot of times people don't list all their yarns. For a while I had a TON of Sugar & Cream I'd totally be willing to part with, but it wasn't listed on my stash page. I recently rectified that after needing some more yarn for a project and thinking about how I could help others, too. Now ALL my stash is listed, even my leftovers!!
Rav also has a deStash/ ISO group you could post on. The limiting factor for that is there will always be more people looking at that forum that need something, rather than who have something. That's why the stash page is so important!!!
Good luck, running out of yarn SUCKS! What are you making? There could be other work-arounds too if you can't get more yarn...