Those Italians are mixed with Brown Caucasoids though (Arabs, Persians etc) and those Blacks are mixed with Caucasoid (which is hence why they have a straighter hair and narrow noses etc). Most Africans do look a certain way and they are certainly not the most diverse - Caucasoids are the most diverse in Hair color, eyes color, skin complexion. Sometimes a genetic defect may occur - giving any race very pale skin such as that Nigerian couple you mentioned. But in general if someone Black has light brown skin, colored eyes and hair they are most definitely mixed race - same with the Italians and Greeks there are White Caucasoids (most Europeans) and then there are Brown Caucasoids (North Indians, Persians, Arabs). The Italians are a mixture of the two along with some other Southern Europeans - it is an inevitable fact that lighter skinned blacks are mixed race, different people will have different opinions but I am just going according to simply genetics.