Those potatoes are dyed with water-soluble food coloring (or colouring, if you're in one of those countries). In this way you are fooled into buying plain ol' white potatoes instead of the ones you really wanted. If you dig about three feet under the bottom potato you'll find that the soil yields a red color (or colour, if you must) if you let it sit in a jar of water. That's from the dye used, unless someone has snuck in and buried a body under your potatoes and in that case you should notify the police. That's an inconvenience, yes, but unless you did it it's your civic duty. If you did it you shouldn't talk about your potatoes.