Trying to get people to change problematic behaviour, language, or opinion through yelling, or shaming is ineffective most of the time. Obviously I can't expect people who belong to minorities to not be angry, not everyone can be Daryl Davis, but if you are white and don't have a personal trauma, you should use more effective methods to correct people's problematic behaviour.
Source: I was able to get my family to stop using the N word, and even my elderly father who doesn't actually remember that it's bad to use the N word has stopped using it thanks to this very simple technique: every time he says that word, stop the conversation and explain why this word is harmful and dangerous to use, don't let them steer the conversation back. Being visibly angry with them will only make them dig in their heels and seek comfort with other people who are racist, making it more difficult to get them out.
Eventually they will subconsciously stop using that word, simply because this causes the conversation to be interrupted every time. So while I don't punish them (can't exactly tell my father to go to his room or something), the repeated inconvenience of having the conversation halted every time will get it in their head eventually.
I think this is the most effective method to correct problematic behaviour in adults.