Honestly, isn't a lot of real-world racism primarily cultural and less about skin tone, even in the US? As in a lot of objections on minorities boil down to "they aren't like us (culturally)"?
I'm beginning to wonder more and more if most racism really is some form of xenophobia actually.
I think this is true in a lot of cases, but a lot of it is so ingrained- at least where I grew up, in rural Northern California- that there isn't an objection behind it, just a matter of how people are raised. It's ingrained and unconscious. I'll give you two examples- as a kid, the only kid around my age close enough to be my friend had a Confederate flag on his wall. It never even occurred to me to question its place there, because I didn't even realize that it was objectionable for many years. (It didn't help that the Dukes of Hazard had it emblazoned across the top of their car, and in fact, I suspect that is why my neighbor had it.)
Another anecdote from my childhood: When I was in 6th or 7th grade, I had a book from a series called Truly Tasteless Jokes (probably number 7 or something). I read a joke that I now recognize as being totally dehumanizing and racist, but at the time I simply didn't understand it- it revolved around the idea that bowling balls were the eggs of black people. I even told it to someone at school once, hoping that their reaction would help me get it. I didn't do that as an act of intentional racism, but looking back on it, good God! No matter my intentions, I was repeating a horribly racist joke, and it didn't even occur to me to question whether telling it was a good or bad idea. Now I recognize how awful it was- I am aghast at my younger self's obliviousness- but neither I, nor the kid I told it to (who also didn't get it, I don't think) realized what I was doing at the time.
And I guess yeah, that joke was about xenophobia- after all, "real" people don't lay eggs- but the meaning was lost on me, and I still told the joke. Awful, but unconsciously and unintentionally so. It's not that I intended to dehumanize anyone, but I was doing so anyway. I was just trying to be funny. Gaah.