I'm white so I haven't encountered racism directed at me but I have encountered it directed at others.
I used to work in a job where our main role was administering payments due to customers that were based on their circumstances. We dealt with both letters and phone calls, inbound and outbound. It was very cliquey and the team I was on were among the worst for it. There was a group of 4-5 people on the team who would read out any "foreign" sounding customer names and make a comment such as "oh here we go... Iqbal Singh. What do you reckon? Five kids, all the business profits in his wife's name, and will expect me to book an interpreter?" Then after contacting him they would reel off which points they were correct on. They would turn their mics off during calls in order to mock customer accents or make remarks such as "learn English" and "wish I was black so I could claim loads instead of coming in here every day". One woman really resented having to use the interpreter service and was very vocal that "people who speak enough English to fill in the forms shouldn't need an interpreter to speak to us". She would tell these customers she was getting an interpreter and instead would leave them on hold until they hung up, sometimes it would take anything up to an hour and it was an 0845 number. They would pass comment on the amounts being paid and make remarks about how they bet it would be wasted on designer clothing that was only going to end up full of knife holes anyway. They would remark that it was rarely the wives calling up because "they don't like the women knowing how much money is going in and out". Really awful stuff.
They would try tell me how to do my job. If I was working a case they'd ask me why I was bothering processing "their forms" and to sift it back to the bottom of the pile "they can wait".
When I said I wanted to do my job properly I got a reputation for being stuck up and that I thought myself too good for the job.
I complained to our manager both about the attitude towards customers and the attitude towards me for not doing what they were doing. The manager told them to tone it down but in a really wishy-washy way so of course they didn't. I complained again and our manager took me into a meeting room for an informal discussion about my attitude, that I was being deliberately difficult, and that I was making myself unlikeable and was not a team player. I was told to join in more with team camaraderie, to stop being a tattle tale, and to grow up, that other people were entitled to their opinion just as much as I was and I was confusing normal office banter with the very serious decision of racism. Did I not know that those accusations could ruin careers? And just theirs, it would ruin mine too because people wouldn't want a co-worker who they'd be afraid was going to get them into trouble the first time she misinterprets a joke.
I couldn't quit because I needed the money but I did ask for a transfer to a different team which was granted however my manager told my new manager that I was immature and difficult to work with. I was warned not to bring any of that silliness with me to the new team. I ended up leaving not long after and last I was aware via a couple of friends who still work there, those 4-5 colleagues are still there and are still just as unpleasant.
FIL occasionally comes out with rubbish about people coming here and taking our jobs, stealing our benefits, that you're more likely to be hired for a job role if you're not white because of "quotas" 
I usually ask him "why's that?" and "what do you mean?" and let him toe himself in knots.