My parents come from north africa (Morocco) and I am white. My grandfather from my father side had grey eyes and was very white, my grandfather and my grandmother from my mother side are skinny but not enough to be considered as black. But I have black and skinny cousins.
And I am not arab since my ethnic community (berberians) was the first to be in Morocco (before the arab invasions). But I don't really know what kind of meltings have occured.
During the last two years after some searches I noticed that the berberian dialects in my village had some similarities with the dialects we could find in Egypt, Yemen, Niger, Mali.
The reality about the other regions in Morocco that you cannot find in other countries like Algeria or Tunisia is that Morocco is very diversified : you can find all kind of origins (arabs, berberians, black descendents of slaves, jews, spanishs, portugueses).