We are blended as well. DH is white, I am Latina, and SD is a different race (not mentioning because I don't want to divulge too much about myself). 

Anyway, in our case SD doesnt seem to understand she is a POC and has made offhand remarks that her dad's skin color is her favorite skin color. She also made a racist joke that she learned from school. We've talked to her about it. 

But I think DH is wary in telling her what she is racially and what that means in the big picture. Idk why. I have been well aware of who I am ethnically my whole life and I think it's a good thing.  

I'm in a biracial blended family (won't say what I am exactly, BF could be lurking) and I haven't run into this problem yet and hopefully I won't, but won't be surprised if I do. BF has told me about racially insensitive comments his son has made in the past but he nipped it in the bud. However, his two kids live and go to school in a neighborhood that's predominantly white and he's hesitant about bringing his kids around my family, so these kids barely experience any diversity. 

I've also been told they're BM and her family are racist, but hopefully they'll keep they're ignorant comments to themselves because of the fact that her kids have a mixed race half sibling. I'd just have BF handle it though if they said something I didn't like, unless they directed it at me or our DD or used an absolutely unacceptable, racist term. 

Sidenote: I've gotten the feeling that BF's family may also be racist just not openly. The type to say and act like they love and accept all races, but make offhand comments when they're only around their own race.

my husband is asian (chinese mixed with malay), i am eurasian. My kids are 1/4 white but look whiter than me while 3sk are pure asian.

mu husbands exwife has always had to one-up people you know like be better so if you were talking and mentioned your kid is at uni she would reply with mine graduated honours, if you have 1 kid well she has 3

anyways its bloody obvious she has told her 2 dark skinned daughters to pack on the makeup so they are white like my kkids which is stupid as they are like 10-15 shades darker than my kids.

their mum is anti Caucasian/anti western anti-white people. Basically brainwashes her daughters we are bad people because we aren’t asian.

i’ve had enough of their crap and have disengaged

One day during the first year my SS lived with us 80%++ (BM couldn't be bothered to even be interested in spending time with her son) and was 13 years old, he broke out with a racist joke that had a caricature impersonation and vocal tone - very clearly a well-rehearsed, well-enjoyed pantomime. I was sickened, and immediately told him that was extremely inappropriate and not how we talk EVER at this house, to not ever let me or God catch him saying anything like that again. 

That was the day I knew his BM is racist. SS grew up hearing & seeing that ugliness as normal, even funny, when she had 80%++ custody (did a lot of withholding SS from DH). I grieved that he had to grow up that way. 

DW, SS and I are all of European decent.   

SS's two youngest half sibs are biracial.   He has never expressed a racist thought that I have ever seen and neither have his mom or I.   

SS is also gay so his perception of racial, cultural, ethnic, gender or sexual orientation differences is that he basically does not see them.  We raised him to be engaging and respectful of others.  With no delineation regarding any classification of others.

As for food, he is the ultimate foody, pretty much like his mom and I are. Except for Mushrooms. He hates them. He gets that from my dad.  SS loved shrooms until he was about 4 and we were visiting my parents and my dad went on a rant about toadstools.  

So no mushrooms for SS. We often cooked with them and if he didn't want them he could pick them out.

We pretty much followed the "you eat what you are served or you starved" model of nutrition for kids.