you'd really need a pre-1900 pod for this to work, but in my mind, it would be three step process. firstly, the early dutch settlers intermarry even more with the native africans, leading to more cape coloured. this could be accomplished by laxer racial views on the part of the dutch, think of the portuguese idea of lusotropicalism as a model for this. second, the british still take the colony from the hands of the dutch, and they bring a lot of white, anglophone settlers with them. this creates a dynamic in which english-speakers constitute the majority of european descended south africans, the opposite of what it is iotl. this might also mean that apartheid does not get constructed, or at the very least, it doesn't get constructed in the same way, as it was centered around afrikaner domination over the country. the british also import more labourers from their asian colonies, leading to a higher asian population. assuming every group gets to comprise between 10 and 20% of the country, we have a south africa that is majority non-black by the present day.