I've only been attending for 10 years, so I'm not sure how long the shirts have been around, but I know that I had orange ones from 2005-2008 and it seems there were older ones than those at the event. I'm pretty sure that 2009 was the first change in color (yellow) and I remember looking around when we got there and thinking what happened to all of the volunteers? If they don't want to go back to orange, could we at least get some day-glo or something that stands out in the crowd?