I don't think a foreigners, especially those from outside of Europe, are judged by their hair color in Poland. Since there's not many of them in Poland, especially those of a different race, they are just named by a part of the world they came from. And it has nothing to do with Germanic race typology, like you've mentioned before.
From my experience, almost all Poles are brown-eyed blondes - and people around say that the most popular hair color is brown.
In where I come from (NE Poland) majority of people have blue eyes and brown hair, blondes are not uncommon but redheads and brunettes are rare. That's too bad cause I like Celtic redheads :-)