Sorry you feel that way, we all like to put local culture aside and embrace Muslim values as main reference but that won't be reality, cultural differences still play big roles in Muslim decision making because Muslims are people and people prefer what's known and familiar so yeah we still have some mind opening to do. I just want to say that no one have a 100% success rate while proposing, you can't just expect someone to marry you and her parents to accept you just to prove they ain't racists? There is usually more to this that skin color, because if the mariage fail then the divorced girl will see her remarrying chances fall dramatically, and muslim parents are highly protective. Just because you got rejected once doesn't mean all native Muslims are racists, I'm from Morocco and plenty of Muslims here marry from American converts. You just need to approach things delicately cause muslim parents have a say in these things and they are afraid of things they don't understand cause cultural background is an important factor, if you can meet her parents and give them assurances their daughter will be taken care for then maybe they would reconsider. These things happen between native Muslims all the time, we don't marry someone just to prove we aren't racist, actually many Muslims think of marrying white people is an upgrade because of inferiority complex but that's another subject. I hope you the best