I remember in South Africa, only white people were allowed on local TV.
My understanding at the time, was white people lived in South Africa and blacks were migrant workers who came over from their tribal Homelands and then returned to their lands, farms and cattle in the holidays. For me, they were from some exotic African countries which I knew nothing about. I had never even heard the word 'apartheid' before, not in school, nowhere, everything was just normal the way it was.
All adverts only had white people. It was like they did not exist. Not in shopping malls, not in skating rinks, not anywhere and where I lived even the labourers and skilled workers were not black but Coloured (people of Khoisan or 'Bushman' descent). In the Cape of Good Hope, blacks were not indigenous to that part of the country (first contact with blacks was only 150 years after Dutch settlers arrived, and they never settled within that Colony) and were not allowed to work or live there.
What was hilarious was when the the government started allowing blacks to enter white areas, the adverts did not change they just replaced the white actors with blacks actors, frame for frame in the exact same advert!