Dominant Kitten...please help!?

IU would remove the white one (to another part off mom) and let the ginger feed, mom's milk is vital, and since it is there and mom is available, it makes no sense to not try all you can to let him get mom's mlk. Make sure he gets his fill daily, even if you have to do something like put a cardboard sheet between them to make sure the white one does not hog all the teats. You will have to be vigilant and keep a really close eye on him daily.