That is exactly WHY so many POLES have differences in their complexions. Some light, some dark, some in between . Mixed ethnicities
Ok, somewhere along the line, you heard that Poles intermixed with Jews often. This is false. As long as Jews have been living in Poland, there has been very, very little intermixing. They kept to their own communities for hundreds of years, and that is why so many were easily picked out by the Germans when they invaded in '39. Most still had Jewish names, Jewish features.. etc. If they had been intermixing, don't you think that it would be just a tad harder for the Germans to find them out??
Dark complexions... mixed ethnicities, this is true. But please don't get Tatars mixed up with Jews. Many Tatars have assimilated into Poland over the years, and that accounts for a large percentage of Poles being olive skinned, slightly slanted eyes, etc. Especially around the Vistula River..
As well, there are many Russians, Ukrainians, you name it, that have been interbreeding with Poles on Polands eastern boarders for centuries. Many of these people possess Asian type features because of the proximity to the steppe.