I also point out, that the Father of the Arabs was Light to begin with. Abraham from Mesopotamia, now modern day Iraq. Thats why Jews and Arabs are not considered black, but white.
I do agree there have been inter-relatial marriages but that is another issue. The issue is that an Arab does not mean genetically always brown skinned by default in any way. Because of the blood lines, of the Semetic peoples from which Jesus, Abraham and Mohamed come from, period!
I will try to find more information if you need it. We both have very good points and I do agree with you on your information, but that I add, I have been associating with Saudi Arabians who have been light and who have been dark who have never married outside their bloodlines and they do vary. Some Egyptians I know personally very good friends with who have never married outside of their bloodlines ( in reference to Hajar, the mother of the Arabs ) are so white they look as though they are from a cold climate. Semetic is a broad spectrum of light to golden tan peoples. Of course under extreme heat and sun, skin does darken. OF course you know that is true.