I’ve seen red potatoes, not purple; they’re apparently very popular in South America:
http://healthyeating.sfgate.com/purple-potatoes-nutrition-2182.html
One of my Filipino coworkers used to bring a purple yam dish to our potlucks. Everything she cooked was scrumptious! P.S. Hope you’re all better.
A long time ago at a farmer’s market I bought purple potatoes. I could not get past the color. I am sure it’s a psychological thing. White pumpkins creep me out too!