Higher rates of red hair in Belarus, Poland and Ukraine could be the result of migration from Scotland and the Holy Roman Empire.  Otherwise it's quite rare and, I had the understanding, that most Slavs (traditionally) associated red hair with Jews.

I remember hearing that during the Spanish Inquisition they would look at red hair with suspicion that the person is a Jew. I don't think it's just a Slavic thing. Don't think it was a Scottish thing lol.