People who tend to be racist mostly do not interact with other races, because they keep within their circles. They never get a chance to disprove their ignorance. I think exposure is a huge factor against racist attitudes. The other thing is fear, fear of what exactly, the unknown. Exposure is the thing that helped OP's husband.

These grandparents could add so much value to your child's life. Is your child not meant to interact with his/her cousins as well? So when the cousins meet up and chat about grandparents and your child never gets to see them...

It really looks like if/when it comes down to it, if your husband has to constantly deal with his parents putting his child down. He will do right by your baby. Trust him on that. But if you force issues, without even giving them chances. Thats right chances, this is learned behaviour that has to be corrected. The emotional toll of cutting you in-laws out is going to cause resentment.

Do it now, while the child is young, it is going to be a process andn you will have to be patient with them but you have to try.

If it matters I am black.