It's also taboo for white people to call some non-white people racist but then we can't actually have a discussion about racism.
Everywhere you go on Earth you will find racist people, whatever 'race' they are some will be racist against other 'races'.
Specifically regarding your point: there are people who are black and racist in the US or any other country.
There's a very important distinction to make between those that write the laws and those that don't.
But racism does not start there.
Racism builds systems of governing and laws that can be racist. Ergo, you see structural racism (again, redlining) which can exist long after the racial zeitgeist has passed.