It might be a new variety but purple taters are nothing new. The Spanish reported finding purple(and many other colors) potatoes in South America in the 16th century while they were there screwing with the Incas. Also they are pretty popular at farmers markets as a novelty item. I picked some up a couple of weeks ago at the Phoenix Hill market.
As a side note,when my Dad was at USMMA Kings Point, the cadets were often subjected to various government testing. He was telling me at one point they dyed all the food in cafeteria different colors. For a while they had blue potatoes and green colored meat. Not surprisingly the amount of food consumed dropped significantly.