An American saying he has never been to Europe, without saying he has never been to Europe.

Barely 2/3 of the population of Zürich is even born in Switzerland. It is true however that most of the immigration is from the EU. But Zürich (and Switzerland in general) is rather the outlier here. Big European cities tend to be anything but ethnically homogenous, certainly not in Western Europe. What is however true is that Europeans don't tend to think in skin colours but ethnic backgrounds, at least those who aren't Nazis.