I think you are looking for the sweet potato vine called Ipomoea batatas Margarita. This is used in planters and other focal areas. It has the light green leaves you are referring to. An easy way to see this plant is to go to
www.whiteflowerfarm.com. There is a search box. Enter sweet potato vine. It will show two varieties - the dark leaved Blackie and the light green variety Margarita. You can double click on these to read the descriptions. I hope this helps.