People of European descent show the greatest variety in eye color of any population worldwide. Recent advances in ancient DNA technology have revealed some of the history of eye color in Europe. All European Mesolithic hunter-gatherer remains so far investigated have shown genetic markers for light-colored eyes, in the case of western and central European hunter-gatherers combined with dark skin color. The later additions to the European gene pool, the Early Neolithic farmers from Anatolia and the Yamnaya Copper Age/Bronze Age pastoralists (possibly the Proto-Indo-European population) from the area north of the Black Sea appear to have had much higher incidences of dark eye color alleles, and alleles giving rise to lighter skin, than the original European population.

-Eye color (Wikipedia)