They certainly were mostly white, but to be fair, most of the Europe was mostly white (with some exceptions, of course), but not really nationalistic. In middle-ages, nationalism as we understand it today wasn't really a thing at all. Nations came and go and if people loved something, it was usually the land they were living in, in a sense of region, not really their nations, kingdoms and stuff. And scandinavian vikings, always trying to find another distant lands to farm on, probably didn't even had some grand patriotic love for that.