Based solely on context clues, it looks like barbarians were areas/regions where civilizations that were considered uncivilized based on European standards but had some semblance of culture and value as a people. Savages were basically people they deemed had no culture or value to them. Not saying that that’s true, but strictly in the sense of how the map values people in those regions

For example, Greece/Turkey and China are barbarians. Well, we know that they each had great empires in the ancient era. Africa would be my strongest argument against my theory, but they also traded with African tribes and this was during imperialism.

Savage areas look to be where Native American tribes, the Amazon, the Kalahari desert region, and Aboriginal tribes heavily existed during that time... and I guess Siberia (idk much about it). Places where civilization has and still is largely untouched or where were straight up genocide was committed from “civilized” countries.

Again, just a theory. Don’t take my word for it and definitely open to hearing others’ opinions.