being mixed-race in america is a fucking trip because having passing privilege really does clue you in when you're young to how much 'whiteness' is a conferred attribute that can be revoked at any moment
or, to put it another way, 'white' is not a race, in the sense that multiple ethnically-caucasian subgroups were NOT considered 'white' until relatively recent history, but it is -about- race, in the sense that it is about what one must be and do to not have their race be used to discredit them
Irish people weren't considered 'white' until the 1930s. Italians weren't white until the mid-late 1950s. White is not an actual ethnic group, so much as this big umbrella of 'normal' that is used for the consolidation of cultural capital into a single bloc; because whiteness can't be intrinsic, it maintains its authority instead by the threat of discommendation FROM whiteness; just look at how America treats 'white trash' culturally
Scientifically this is utter bullshit either. Everyone in Europe, Western or whatever else, is quite a mix of ethnicities, as seen in DNA testing. Especially in Europe, which had thousands of people moving there and back over centuries and, naturally exchanging genetic material all the time. You can speak of a dominant haplogroups in case of most people in Europe, but any concept of "racial purity" is no different from "pure proletarians" in Marxist utopia I'm afraid.
Each of which is a mix too. Apart from some very closed or isolated ethic groups there are no "pure" ethnicities in the world. The former on the other hand frequently suffer from all kinds of genetic diseases as result of inbreeding. The very point of evolution is elimination of defects by gene mixing, and humanity has been practicising this happily for millenia.
These are phenotypes, so how people look like. You can have similar phenotypes from different haplogroups. In Europe you can find a whole range of these, from H to N, R, U etc. None of them have hard borders, they can be only described in terms of probability distribution.
You have blonde blue-eyed Aryan ubermensch with both H and R1a mtDNA. And possibly others. So what?