Children learn racial bias by age 5. So sadly, but the time parents are willing to talk to their children, they've already developed some racist beliefs.

Toddlers as young as two years use racial

categories to reason about people’s

behaviors (Hirschfeld, 2008),

I agree with you that children are taught this but I think people underestimate when this bias develops. It happens much earlier than most realize.

https://inclusions.org/wp-content/uploads/2017/11/Children-are-Not-Colorblind.pdf