We don't get to see much of Andy's little bro, Monty, but we hear about him from Andy. Check it out:
The only one in my family who is really cool is my little brother, Monty. But I worry about him. I think when he gets to be my age, he's goin' to have a lot of problems. I know he's only six, but he doesn't think black is cool. And he's got this thing for little girls with yellow hair—yeah, I worry about the kid sometimes. (11.64)
Hmm… Andy worries about Monty because of his fascination with blonde girls. This might seem harmless at first, but Andy thinks it means a lot more than a crush on some cute girls—he understands this as his little brother liking white people more than black people, and thinking they are better, which is a problem. Unfortunately, though, Andy will never know for sure since he doesn't stick around to watch his brother grow up.
The few times we see Monty, he comes across as innocent and well-meaning. So Andy's concerns about internalized racism aside, we're rooting for Monty as he tries to find his way forward in life without his big brother.