Even though Grey Eyes are considered a darker shade of blue, they are actually the lightest of all eye colors because they have the least amount of melanin. Looking closely at a grey eye, you could see it's clearly lighter than the average blue. Grey eyes are seen mostly in Northern and Eastern Europe such as Finland, Russia and the Baltic countries and, of course, their descendants.
Grey eyes appear to shift in color between grey, green and blue. This, again, is due to the fact that the grey eye is extremely light and reflects the colors surrounding it.
Grey eyes are of indo-European origins and could only be found naturally in people of European heritage. It is possible for those of Asian and African races to have grey eyes. However, it is due to white admixture marked on both sides of the subject's family ancestry.
Grey Eyes - Black person w/Grey Eyes from white admixture
Grey Eyes - Non-white person w/Grey Eyes from white admixture
Grey Eyes - White gentleman w/Grey Eyes