Litvish, the premise you’re basing all of this on is that the Jews should naturally have dark skin. Like I said before, this is baseless. The reason the middle east has dark skin now is because one region mixed with all the others after Islam and dark skin tends to be a more dominant gene.
Multiple posters have pointed out to you that certain groups of Sphardim are not particularly distinguishable from Ashkenazim. You seem to be zeroing in on a Teimani/Mizrachi stereotype to define all Sphardim. Sphardim from Morocco, Egypt, Rhodes, and Turkey are not brown skinned (obviously some might be).