Most think the youngest age it's appropriate to talk about race is age 5 or so, as they are ready to start kindergarten. This is too late.
A short thread.

We have years and years of research on children and their recognition of race. We know that 3-month-old babies already show preferences for faces that reflect specific racial groups.

By 9 months, children begin to categorize faces by perceived race-- this person is White, this person is Black. And by 3 years old, they are already associating Black faces with negative traits.

By age 4, a year before most people think it's appropriate to talk to kids about race, children already link White people with higher status and wealth.

By the time kids enter elementary school, researchers find that race-based discrimination is everywhere. Just as parents are beginning to have conversations about race, their children are already stereotyping others because of their color.