Kindness is such a broad word. It is truly relative to the person in question. For me, kindness is the simple act of having decency or going beyond that. Doing nice things, or just simply treating one another properly are all examples of treating others with kindness.
Sadly even now some people, because of the color of their skin, do not get the simple respect and kindness they deserve, for reasons they cannot control.
I think taking steps to fix this issue would be considered an act of kindness. At least reaching the goal of decency and going above that, would be absolutely amazing, and with each act of kindness we do we get closer to that goal. I think some acts of kindness to keep progression on this matter moving forward would start at school, where the children of the next generation are imprinted with certain main prospects of life, one of those hopefully being to simply be kind to each other no matter what.
 Adding more education about the past and actually acknowledging the mistakes made, could be a crucial step in this. Perhaps bringing more true information to the curriculum, and sorting through what is already being taught could act as a filter to go through the information that is being presented to students. Having more than just a day or week to talk about these ever-present issues isn’t enough. Implanting these good values into the lives of students, into core academics, could really make an impact. Reading more into the questions, “What is really taught in history?”, and “How is it brought about?”, are important to evaluate if what students are being taught is up to date and factual, and perhaps necessary. Expanding ideas by expanding libraries and adding educational books is another excellent way to really ensure children of all ages are being taught the right things. Hopefully if it comes at a young age, as the children grow older their surrounding environment can not sway them of their core value.  
This obviously is a huge undertaking, but nonetheless, still an act of kindness, a large one at that. Although, I think it is due, or perhaps even late because changes like this should have happened a while ago. I think this is a greater act of kindness, one for everyone in the past, present, and hopefully not the future who have been affected by discrimination and racsim, because that should be a thing of the past.