from my understanding it basically means, people who benefit off the contributions of black civil rights advancements, while at the same time looking down on or acting in opposition to the people who brought them these benefits. and sometimes even the benefits themselves.
Tariq exclusively refers to black immigrants when he says this, but i think it can also be applied to the LGBTQ community, Asians, Mexicans and white woman,
One example would be Asian people and their stance on affirmative action. Affirmative benefits people of all races and requires colleges to essentially practice integration and accept people of all backgrounds. Asians have benefited from this as much as anyone else, but they are against because they naively think if it was abolished, colleges will admit even more Asians and allow themselves to become 95% Asian colleges.

I guess they think if they get high enough grades these white colleges will favor them over white applicants

unlikely. There was a time before aaction, they weren't recruiting in you droves back then though remember?
What would happen is the colleges would go back to favoring the wealthy rich white people. (which they still do anyway, but it would be further magnetized.)