Yes, there is a chartreuse sweet potato vine, "Marguerite". It really is chartreuse, no kidding!

BTW - sweet potato vine does best in full sun, it doesn't get as lush in part-shade.

Also, in regard to starting one from a grocery store potato, sure you could, but it probably won't be the color leaves you're looking for. If you don't have your heart set on chartreuse leaves, this would be a great inexpensive alternative. "Marguerite" is readily available when the annuals are put out, sweet potato vines have become quite popular. You can save the tubers that are formed and use them next year, too.

Thanks! I will start some from some sweet potatoes anyway for the fun/experiment of it. I will then get some in the chartreuse from the nursery. Re saving the tubers...how do I store them? I am in zone 5 - good and cold for about 6 months. Can I store them like I store my bulbs?

I stored my chartreuse potato vine tuber at room temperature last winter, and it was just great when I replanted it in the spring. Also, you can take tip cuttings all season that will root in water within days, and those can be potted up as well. Once you've bought one plant, you'll be set for life! Bought one--what am I saying? I got several slips off commercial plantings that were all over the sidewalk a few years ago. They are amazingly prolific, and set off pretty much any other color beautifully. Love the purple ones, too, but they aren't as generous. I have a couple of pots of them overwintering in a sunny room--don't know how they'll do.

Last year I got a two hanging pots of sweet potato from Wallyworld (Marguerite and Blackie) Each pot had 5 plants in it as was probably $10 each. I took them apart and planted in the garden. I love how they just sprawl all over the place! Now if only I could remember to dig them up in the fall!