That's how they look like just after harvesting. Flesh is light yellow, after cut fresh tuber in half, milky juice appears (it's also visible on damaged roots on pic below).
Tuber grows:
Vines are not able to climb. The plant creates much more vines than Beauregard for example and leaves are much larger. Also, they are mature very quickly, I think 2.5-3 months is enough if summer is hot, but I got pretty good size tubers even after 2 months (but most of them were small)