I have not experienced racism personally as far as I know (I'm white) but when I was a kid, my Dad landed a job at coal mine in South Africa. He endured 2 years of racism from the Voortrekkers ( White Dutch descendants) who ran the mine. It started on his first day. After arriving he was taken by his boss to a bike shed. His boss explained to him that the blacks were there to do everything they were told without question. He then called over this poor black guy who just happened to be within shouting distance. The boss told this man to remove his helmet. He then urinated into the helmet and handed it back to the black guy, telling him to wear it, which the black guy did.
My Dad was shocked at this but he'd just moved his family from the UK to South Africa to start a new life so he figured he would persevere. It soon became known that my Dad got on well with the black guys at the mine. He'd chat and crack jokes with them and help them where possible. The Voortrekkers saw this and simply ignored my Dad when he sort help, calling him a kaffir lover. My Dads life was hell and after 2 years of being treated like scum, he finally gave up and we came back to the UK.
Ironically the racism my Dad suffered was white on white.