For those that didn't know, there was an earlier silver version of the KC06, which I believe was tried and reviewed by @bhazard. It wasn't good. In order to ensure you got the newer, updated (awesome) version, people were buying the gold one. The risk of getting a silver one was that you couldn't be sure you got the awesome version.
Nowadays however, I doubt there are any older versions left. I myself bought a KC06 from Shenzhen Audio, the golds were sold out so I got a silver one. I contacted them and they assured me that it was the upgraded version. You can scroll back to see my reviews.. my silver KC06 is indeed awesome. :)
Though Ostry told me only the packaging was updated, it still makes me wonder if they fine-tuned the latest original "silver" KC06 because while I was reviewing it and comparing my notes to 5 month old reviews from others, my impression were slightly different. Either way, just to confirm as you have seen from my KC06/KC06A review comparison, they all have the new packaging and updated set of tips.