I think, you can't change how people feel about you. But then again, it's not your problem but theirs; which they have to deal with. And i'm sure it hurts and drain them more. On top of that, the negativity of their thoughts are toxic for the environment around them. All of these are just feelings that may come and go in time. There are many reasons why people feel and react the way they do. Sadly, the reasons are mostly, misunderstandings, misjudgment and some mistakes that they are hardened to forgive and forget.
How to deal with it? Depends if you see each other on a regular basis or not. It would be hardest if you are staying together. If you have tried to resolve the matter in the past but hadn't succeed, don't give up. He or she just isn't ready to let go yet. Maybe you can try to talk to the person again one day. In the mean time, don't beat yourself over it. Whether or not you have done anything wrong that transpire the whole situation; remember that we are all human being. You and I are not free from mistakes and people can be a victim of discrimination too.
Best you can do is, to be patient and strong. Try not to get affected by it and refusing to let this person/incident get to you by altering the best of you.
In the end, kindness and forgiveness always wins over anger and grudges.