Her parents feigned whiteness. So what color is she?

Marion Campbell is an Afrikaner who owns her own boutique travel agency but who has an intense personal dislike of visiting new places. This seeming contradiction is child's play in mid-1990s Cape Town, where neither people nor things are what they appear. In the new South Africa, nobody will admit to having supported apartheid: "Even though she voted for the Nationalists, she knew deep down that those policies were not viable. But what could one do, short of joining the hypocritical English voters and betraying your own? Now she understands only too well that the past was a mistake, that things are better now, for instance, things like tourism."

In Zoë Wicomb's delectable novel Playing in the Light, the background is equal parts Table Mountain and Truth & Reconciliation Commission. Although Marion is no more interested in the TRC hearings than her counterparts, she finds herself investigating and coming to peace with secrets she didn't know she had. Not bad for somebody who eschews psychotherapy.

Friends haven't factored into Marion's life much. On occasion, there's a boyfriend, and her father, John, still lives in her childhood home a few miles away. Several days a week, John hears her Merc rounding the corner, and he alternately delights in the presence of his daughter and is humiliated by having her watch him age. They share meals and a love of the sea, but save for these few hours, each leads a solitary existence.

So Brenda, a young progressive poet working as a clerk for Marion, would seem an unlikely confidante. In what should be an embarrassing faux pas, Marion asks Brenda to help her discover what became of Tokkie, her long-deceased part-time nanny, apparently because she believes that all so-called coloureds (mixed-race) have connections to one another. But the crude assumption is correct in this case, and Brenda accompanies Marion on her physical and psychic journey.

For half the novel, we must wait for Marion to discover what we infer much earlier. I don't want to reveal the entire plot here, so suffice it to say that Marion's parents, once coloured, were reclassified as whites during the Population Registration Amendment Act of 1962.

As "play-whites," Helen and John had little playtime. Helen's unexpected pregnancy was riddled with anxiety; even after Marion was born with pale skin and smooth hair, she experienced no relief.

Instead, she relentlessly created new material goals that, she was certain, would lead to deeper confidence about the family's status. But no matter how many lace curtains she hangs in the windows, the possessions never quite helped her achieve her unattainable notions of decency and refinement.

Ultimately, the most impressive marker of status that Helen could show off in her neighborhood was Tokkie, coming in through the back entrance in full apron, once a week and infusing the home with a certain amount of class.

For Marion, however, Tokkie imparted a sense of home and a feeling of family.

John and Helen's particular joy – or, at least, comfort – rested in watching Marion grow up with the confidence and privilege of other white children. They adopted enough racist lingo to blend in. And they sent Marion to the University of Stellenbosch – sometimes referred to as Harvard for Afrikaners – where the architects of apartheid literally gathered to design their master plan.

Once Marion begins to understand who her parents were, she confronts what it means not just for whites to feign innocence about apartheid, but for blacks too. Well, to an extent, that is.

Although she finds that the people on the periphery of her life are all ready to engage her fully, she does her best to maintain her grip on what others know about her until she is sure of it herself: "And if, she wonders – in a drunken state, say, or old age – she were to be lured into telling her story, which part, which anecdote would be selected to bear the weight of presenting her to the world?"

Nothing here is presented or understood as black and white: Everything, rather, is rendered in endless shades of light and dark. As in her earlier works, Wicomb's prose is as delightful and satisfying in its culmination as watching the sun set over the Atlantic Ocean.

• Rebecca L. Weber is a writer based in Washington, D.C.