It is not about about skin color or genetic origin. Whether we exploit a group or not simply depends on whether we can get away with it or not. If humanity cam

It is not about about skin color or genetic origin. Whether we exploit a group or not simply depends on whether we can get away with it or not. If humanity came across a group of purple aliens, how we would treat them would depend on how advanced they are. If they were on the level of advanced animals, we might trap them and exhibit them. Keep them in cages and "study" them. If they were much more advanced than us (maybe the can communicate with us, or zap one of us to death with lasers) we would submit and seek cooperation, and humble ourselves before them.