South Africa has been divided by race since the Dutch landed in 1652 and then the Brits took over in 1806. (there was swapping back and forth). The racial segregation was mostly informal but was a daily fact. In 1948 the National party took over and moved towards formal Aprtheid which lasted until 1994 when Mandela walked.
That's 368 years so it will take some time to unpick those attitudes. You only have to consider that the USA and UK still show discrimination to people with differently coloured skins...