Believe it or not, those "ornamental" sweet potatoes are just as edible as the orange ones.
https://www.gardeningknowhow.c...
I had a feeling that you were talking about the 'ornamental' ones, but when the info is the same....
Incidentally, it isn't just the 'tater' that's edible... slice those leaves into strips, cook like collards, tastes like collards.
I stack a pile of those heart-shaped leaves in the palm of my hand and slice across the grain... not across my hand... I pull in my fingers, and slice the section of leaves sticking out... you can use a cutting board if you like, but I'm grossed out by those things....