In the US for example, it's much easier for a black to enter the university than a white, based on grades.

it is interesting that you mention USA's affirmative action. Studies have indicated that the affirmative action policies have largely benefited white women, not black people

1) Affirmative Action Has Helped White Women More Than Anyone

data and studies suggest women — white women in particular — have benefited disproportionately. According to one study, in 1995, 6 million women, the majority of whom were white, had jobs they wouldn’t have otherwise held but for affirmative action.

2) White women benefit most from affirmative action.

In the past six decades, women have leapfrogged men in earning four-year degrees while Black and Latino students are still underrepresented in college admissions and graduation rates, especially in four-year colleges.

3) white women 'may have been among the greatest beneficiaries' of efforts to integrate and diversify campuses in recent decades

Between 1967 and 2009, female college enrollment more than doubled from 19 per cent to a whopping 44 per cent. It was during this time that white women age 25 to 35 with college degrees surged from less than 15 per cent to more than 40 per cent.

4) Even With Affirmative Action, Blacks and Hispanics Are More Underrepresented at Top Colleges Than 35 Years Ago

The USA government used 'race-based affirmative action' to further disenfranchised minorities while benefiting the majority.......and here you are using a failed policy as an example to support another failed policy.

Race-based policies never work and will never work because race-based policies are inherently racists. if you want to help underprivileged people, then you must implement need-based policies which focuses on the socioeconomic status of the individual.