Agreeing with the posters above, those lenses are not exactly in high demand so they will generally only be available in custom.
I do know of one place selling "costume grade" double iris lenses but they are white. I am linking it anyway as they may expand the color choices in the future so it might be something you wish to bookmark.
In the meantime, if custom lenses are out of your price range, regular gold contact lenses are the next best option for you. If you scroll down to the 2nd post and look for the tags about gold lenses, you can see a number of recommendations: http://www.cosplay.com/showthread.php?t=230059