Okay, we know everyone's first human ( sapiens) ancestors are from Africa but....?

If you consider yourself "white" right now, but somehow, in the near future, find out that one of your ancestors from a couple thousand years ago (before the Saxons migrated to Britain) was from Africa, would you still consider yourself "white", or would you adhere to the defunct "one drop rule" and say you are "black"? What would you do if that's the case?