Probably the biggest deterrent to erosion is a grass or sedge. They have fibrous roots that grab and hold the soil, and keep it from slithering away. We realize you specified adding some color to your area, and some of the grasses do have color and can be very attractive. We will select some blooming groundcovers and some grasses that we feel would address your problem. To do this, we will go to our Recommended Species site, click on North Carolina on the map, and then NARROW YOUR SEARCH, selecting "Herb" (herbaceous flowering plants) under Habit, and "Shade" under light requirements. We will repeat the process selecting "Grass or Grass-like" under Habit. From those, we will be able to pick plants native, not only to North America but to North Carolina, that will thrive in the conditions you specified. You can follow the links to each plant page and learn how big it gets, whether it's perennial or annual, what color the blooms are, etc. These plants are all commercially available; if you have difficulty locating the ones you like, go to our Native Plant Suppliers section, type in your town and state in the "Enter Search Location" box and it will give you a list of native plant nurseries, seed companies and landscape and environmental specialists in your general area.
HERBS (herbaceous flowering plants)
GRASSES OR GRASS-LIKE PLANTS