In Britain we seem to be living in a kind of educational apartheid, in which most of us remain profoundly ignorant about racism and its history. This leaves a minority who have either a lived experience of it or have made an effort to self-educate with the gargantuan task of communicating how racism works, and the language in which it manifests.

It’s unpaid labour, of course: work that is unavoidable in regular interactions with people on the other side of that educational divide. So one of the best things, it seems to me, about Sheffield University’s decision this week to recruit students as “race equality champions” is that they will be paid. The university has been rocked – as have many academic institutions – by revelations of the scale of racism being experienced by its students. A report last year found 13% of students had experienced racial harassment, with some having the N-word shouted at them, or being told: “You’re pretty, for a black girl.” In response, Sheffield has announced that a team of students will work up to nine hours a week to challenge racism and microaggressions, and to identify and lead constructive conversations around incidents. They will each be paid £9.34 an hour. It’s a necessary, if insufficient, response given that the dire state of race dialogue is in large part a problem of education.

But campus racism is a small part of the whole picture, and is mostly ignored by society. When experiences migrate to the royal family, however, and the ensuing debate plays out in our media, the world is watching. The Harry and Meghan saga has brought a global audience to the newly popular British sport of demanding that people of colour share their knowledge of racism on live TV while media heavyweights attempt to silence, shame or undermine them.

Take, for example, “playing the race card” – one of their favoured phrases. I didn’t know I had any such cards until I began to educate myself about racism in Britain. But it seems that when I thought I was offering either a structural or personal analysis of how racism has affected black people’s lives, what I was actually doing was merely playing cards. Yet these magical cards don’t actually work. When we use them, the argument then turns from a sensible discussion into a shouting match. If this is supposed to be winning, it doesn’t feel much like victory.

The real point about race cards is that claiming their existence is itself deeply racist. The idea first seems to have entered the lexicon in the 1960s, when “the race card” was used to describe the ways in which rightwing politicians weaponised fears about black people to gain votes – such as the 1964 Conservative parliamentary candidate for Smethwick reportedly warning his prospective constituents: “If you want a nigger for a neighbour, vote Labour.” These days, it is more frequently deployed to delegitimise the voices of people on the receiving end of those narratives. Either way, the one consistent thing seems to be that it always involves setting up people of colour to lose.

Facebook Twitter Pinterest ‘The Harry and Meghan saga has brought a global audience to the newly popular British sport of demanding that people of colour share their knowledge of racism on live TV.’ Phillip Schofield, Holley Willoughby, Camilla Tominey and Shola Mos-Shogbamimu on ITV’s This Morning. Photograph: Ken McKay/ITV/REX/Shutterstock

As the author Nels Abbey pointed out this week, accusing a black person of “playing the race card” when they speak about racism is intended to silence, threaten or “shame someone into not mentioning the obvious racism they’re being subjected to”. A significant number of British people would like to silence us. But the real tragedy here lies with a far greater number who seek to challenge racism but are unsure how to achieve it. Last week, for example, a teacher contacted me about how she could decolonise the key stage 2 curriculum for her class of eight-year-olds. She was anxious to avoid narratives that exoticise people of African heritage, or feed into imperial ideas about “primitives”.

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While I’m familiar with the problem, it was far harder than I expected to help in any practical way, since the vast majority of resources exist for university students. Those struggling to do the right thing for younger learners rely on the unpaid work of black teachers who have developed their own tools for the classroom.

The lack of value attached to antiracism work is an old problem, but its costs are becoming ever clearer. This week a senior Commonwealth figure told me that the tabloid treatment of Meghan – so clearly racist to observers in other parts of the world, while large parts of the British public remain in denial – is having a knock-on effect in making it harder for him to promote Britain abroad.

No doubt future generations will teach the racism of our media in this moment just as we now talk about Smethwick. Our comprehension is so slow to catch up that we seem only to understand racism in hindsight. Those of us who see it in real time continue to do the work, no matter what the tabloids call us.

• Afua Hirsch is a Guardian columnist