Race is a modern concept and didn't really exist in their thought. They were more...cultural-centric? Not sure if that would be the right word here and maybe someone can come to correct me. Remember there wasn't a concept of "European" and "African" back then.They for the most part only cared where you were born. More of a focus on culture. Romanness=good, German barbarianism=bad. But even "Romanness" could be achieved by outsiders, so I would say that's pretty open.