Racist Mother-in-law

Recently a coworker and me were joking about how our kids/future kids were going to get married. Me and my husband are white with Auburn and red hair and we hope to have red-headed babies😍 She, her husband and beautiful babies are black with dark brown hair. My co-worker joked that she'd love to see a black baby with red hair.

At a family dinner, I jokingly made the comment, "Oh, by the way, I have our future kids betrothed to Lila's kids" just to give my husband a laugh because he is uncomfortable around his mom. When she heard that she replied, "no grandbaby of mine is going to be marrying a black person". I was SO taken back and angered, I didnt know what to say! I calmed myself down and just said, "They can marry whoever they love." Mother-in-law just cut her eyes at me and didn't say any more.

I feel like she makes comments like this way too often. In the past when we've brought up adoption she has said she doesn't want us to choose a black or mixed child. Her reasoning was that he or she would'nt feel like they were really a part of the family because they wouldn't look like anyone... when she could tell that what she said about adopting made me upset (I even had to walk away because it hurt me to my core and made me cry. I mean, who couldn't have unconditional love for a BABY or child, no matter what the skin color), she said she was joking and she would love any baby no matter what.

I know I dont have kids yet (REALLY want them soon) but how will I be able to let them be around someone so toxic? I want to raise my children hearing and seeing Gods wonderful, unconditional LOVE every where they go. I am worried to let her watch them or even be around them when she could say stuff like this and put her horrible racist messages in their minds😢

Advice?