Murphy, Just buying a DK in 2011 doesn't necessarily make it a 2011 manufacture date. They don't sell them by date of manufacturer, they sell them by date of purchase; not that it makes any real difference- the warranty is from date of warranty execution. Boat engine manufacturers do the same thing so as to not have conflicts over when they're put into service. Sometimes tractors, boats, etc. sit a long time before being sold, and this supposedly makes for less confusion about model year, etc.
All I know is my purchased in 2009, DK-35 was grey and orange, and so was the KB-2485 hoe I bought at the same time. The DK-40 I bought in 2010 is (dark)black and orange.