I don’t think I’ve ever seen a white sweet potato.
The white sweet potatoes are not as common. They are richer and taste like honey. They do not need “doctoring up” as much as the red. Back when I grew them, I started with a bushel (ate some, planted some) that I got from a farming family in Sampson County NC. They grew red ones for market, but white ones for personal consumption.
I saw white sweet potatoes in Safeway about 3 years ago but could not spend $4.99 lb on sweet potato.
The white ones are the same shape as the red, and same growing habit.