I took a class on modern African history a year ago, so while I can't say much, I still remember a bit about opposition to Apartheid in South Africa.

White South Africans played a small but significant role in the anti-Apartheid movement within South Africa, especially early on, when opposition to Apartheid took the form of civil disobedience, mass demonstrations, and boycotts. There are many examples of white South Africans fighting apartheid during this period, such as white motorists giving rides to black South Africans during the 1957 bus boycotts, which was itself organized in part by white South Africans.

Following the Sharpeville Massacre in 1960 and the government's ban on the African National Congress and the Pan-African Congress, an increasing number of black South Africans took to violent resistance as their preferred method of affecting change. Many black South Africans began questioning whether white South Africans should play a role in opposing Apartheid at all. Some organizations, such as the United Democratic Front, accepted whites, whereas others, such as those which comprised the Black Consciousness movement, felt that the fight against Apartheid was best handled by black people alone. While there was less white involvement in armed resistance against Apartheid, this is not to say that whites stopped opposing Apartheid altogether. Rather, they continued their non-violent opposition to Apartheid, and began coordinating with opposition movements abroad, particularly in the United Kingdom.

Source:

Cooper, Frederick. Africa since 1940: The past of the Present. Cambridge, U.K.: Cambridge University Press, 2002.