My DC (mixed race) don’t look anything like DH (black). They could be adopted. It’s totally normal to worry, question, be concerned about the implications of this. It’s good to talk these things over. What’s to hide?
My DH struggled with it when the DC were babies. People would look at him walking down the street with them (“has he taken those kids??” I’m sure was the thought going through many people’s minds when they were cute little babies dressed in expensive clothes, or in a fancy stroller, walking around in an expensive part of town. DH looks disheveled at the best of times!).
As they got older and the father-child dynamic was plain for anyone to see, this stopped. It coincided with him finding his feet as a parent and giving zero fucks any more what anyone thought about him/them/it.
Now, years on, he uses it to his advantage when he wants to embarrass them in public. He’ll have no hesitation telling a shop assistant or a waiter or a museum security guard (all three have happened!) “yes well, you’ll have to speak to their parents, they’re nothing to do with me” when they misbehave in public! 😂
It’s fine, honestly. Initially weird maybe, but they’re so undeniably YOUR children that it really doesn’t matter what they look like.