Ok, the deal with that, as is basically stated in the overclockers.com article you just mentioned is that that vendor is trying to screw people out of a few extra bucks. All processors 1GHz and up are made in Dresden, and have copper interconnects. This is what they mean by copper die. So, all 1GHz+ processors have copper dies. This isn't their colour, it's what's used to make them. They're also charging extra for the blue chips because at lower speeds when processors were coming out of both Dresden and Austin at the same speeds (say, 900), the Dresden processors' cores were painted with a blue polish. The copper process used at Dresden gave better yields, and thus better overclocking. So, the blue chips became known as the better overclockers. Now however, there have been several instances of blue processors coming out of Austin, and green ones out of Dresden, as well as red and purple. Colour doesn't really matter as much now, and certainly not for the higher-clocked processors. What really matters is the code (AXIAs are excellent overclockers), and the week number (some weeks have produced better overclocking chips than others). So, like the article said, don't be fooled.