People of Color (Black and non-Black) in the United States can (and many do) hold prejudicial or bigoted beliefs about white people. Whether it is right or wrong to do so (IMO, a strong argument could be made that it is reasonable for PoC, based on their treatment by white people, to hold anti-white prejudices), anyone with an understanding of history can see and fully empathize with why they might. Those prejudicial and bigoted beliefs only affect white people on an individual level. They do not have an impact on the rights possessed by white people. They do not have a collective effect on their economic, employment, or educational status.
In short, People of Color can be anti-white, but they cannot be racist against white people bc they lack the collective power to impose their prejudices on white folks as a racial category. Access to social, political, economic, and religious power is a fundamental component to the system of oppression known as racism (in the same way that access to such power is essential to sexism, which is why men do not experience sexism). Without that access to power, there can be no domination, oppression, or subjugation of white people by PoC.
But what if PoC could be racist? Imagine how different United States history would be if People of Color could be racist. We might see examples like the following: