I know, right! At some point, I thought colourblindness would be a good thing - only to be corrected soon after. I read about racism whenever I come across stuff, but it's hard to know everything - plus insights change anyway. I think the most important thing, though, is to be very conscious and to try and get it right. That's anyway pretty much all you can do, short of becoming a racism specialist yourself. (Only so much time in life!)
I agree that those conversations are super important. We've also had chats about racism, and what it means and what she could do when she sees it. Similar for white privilege. (My youngest is too young for that; and my eldest is also below 10 - so they're not super deep discussions.) But I don't want to stress them out with the subject either, especially since my daughter has lots of non-white friends (to be clear, I'm saying non-white because they have different skin colours; I'm not trying to avoid the word 'black' at all costs), and she shouldn't worry about them unduly or start bothering them with it. Still, I do want her to be conscious of this - especially since she apparently tends to take on leadership roles in class, so she can make a difference. It's a fine balance!
Urgh, so much to consider as a parent.