Tropical Potato?

I have grown accustomed to seeing the bright, colorful, tropical fruit, but these sweet potatoes caught me off guard. I've never seen potatoes as purple as these! You can buy them and ears of corn on the streets from vendors with a cart transformed into a large grill.

I'm going to have to buy some raw potatoes in the market and make mashed potatoes. Just think how amazing a bowl of purple mashed potatoes would look!