There are three varieties readily available in Mississippi. The most popular right now is Blackie, which is a fast grower with green foliage that darkens to a rich dark purple color as it matures. Blackie grows well in containers and as a groundcover. I have combined them in containers with trellised Bougainvilleas, pink verbenas and the old ham and eggs lantana. They were super in all instances.
Marguerite is a fairly new cultivar and produces lime-green foliage.
You may also find what looks to be the same lime green sweet potato vine being sold under the name Sulfurea and Goldie. I have seen Marguerite attractively draping a bridge in Bellingrath Gardens near Mobile. Tri-color is my favorite sweet potato vine. It displays white, green and pink variegated leaves and is as vigorous as Blackie. You would think that the prettiest of all sweet potato vines would have a better name than Tri-color.