If you don't believe in using food coloring, you might be able to color this with a few tablespoons of beet juice. That may or may not add a slight beet flavor to the ice cream; I've never done it myself but I've heard of other people using beet juice as a natural coloring agent.
This ice cream would be yummy served over my single-serve brownie recipe or the Cake in a Mug recipe from the book "Trim Healthy Mama". Sugar-free peppermints sweetened with a sweetener such as stevia, xylitol, or erythritol would be good chopped up in the ice cream.
If you don't have an ice cream maker, blend the ice cream ingredients, stir in the chocolate chunks, and freeze in ice cube trays. Let the cubes soften slightly, then blend them to a soft-serve consistency in a high-powered blender. Firm up in the freezer, if desired.