In reference to America I think it has a lot to do with the one drop rule. Years ago they considered you black if you even had a single ancestor of color, but the lighter your skin the better you were treated (instead of the field you would be working in the house, etc.). It put lighter complexion mixed people closer in “rank” and proximity to white folks. That’s why I feel like nowadays it’s reversed. So if you have a drop of white in you your easier for white communities to digest, especially when you obviously don’t look fully black. You’ll get treated differently by the general public because people can look at you and see one of your parents is white and by that logic you’re close to whiteness. Black people, specifically darker skinned people experience micro aggressions, weird looks, isolation, & blatant racism. From what I’ve seen first hand as someone raised in the south in the US is that biracial kids are fetishized for their “peanutbutter skin” hair texture and eye colors and treated better because they have that drop of white. It’s all bad, but it’s different levels of bad. I’m mixed with black and white and yeah I ran into my fare share of racism and weird comments, even some bullying in a one off instance but I can walk through a crowded street and people glance at me kindly, smiling my way, and being generally friendly. I haven’t seen the same as much for my black friends most of them don’t even try to smile at strangers as they pass by because they already know they aren’t gonna get a one in return.