This particular one has a heart shaped leaf formation and a vibrant dark purple coloration on it's foliage. The tender shoot and new forming leaves does have that brilliant purple hue and slowly fades to green tones when turns matured. The bright lighting does play a role on this one, especially if it is exposed to long-day open sun the whole plant leaves coloration will be in total purple.
If in case, in a season in time where it is not exposed to the long sunlight,
eg: during rainy and cloudy days - this plant will be more in green tones.
Similarly it will turn more green when planted in semi-shaded areas.
I grow my sweet potato vine (Ipomoea batatas) solely for ornamental purpose.
They are trailing plant where they form roots at each node section
They do form edible tubers but I doubt it is enough for me or anyone to consume it.
Basically they are ideal for ground cover and does very well in open / direct sunlight area - doesn't fair well in shaded areas as they will turn faded green and loose the colors.
Heavy Watering - this is a very thirsty plant. Do consider watering it twice a day.
You will notice the foliage going limp or withering when lacking water.
Light - Direct open sun. This plant is a sun lover.
May able to grow in shaded area but it will loose the vibrant purple colors.
Pruning - Do care to prune heavy when they trailing vine gets leggy and spans out all over. The pruned vine can be replanted or rooted in water.
Pest - I had some trouble with this one.
White fly, mealybug and leaf eating insects seemed to be attracted to these. However this is a vigorous growing plant - even replanting with 3-4 leafless stem, they can easily generate into a beautiful plant.
The Flowers do appear like morning glory. This one has pink inflorescent and blooms for a day.
Sweet Potato Vine - Dark Green with Purple Tones
This particular cultivar is cultivated as edible plant.
The foliage and tubers are edible where the leaf color are very much more in the appearance of green than brilliant colors (those are ornaments) However, the ornaments are also edible but rarely used for culinary purpose.
It does grow vigorously and can be invasive which may require constant pruning to keep them in their bedding.
Maple-Leaf Shaped Variety - Dark Green with Purple Tones
This is another cultivar - very much green with slight purpose tones. I believe this is cultivated as a crop rather than ornament purpose. The flowers are are in pink similar to a morning glory.