By the way for your info, Abu Dharr al Ghifari, the sahabi who had the incident with Bilal was described as black in complexion himself.
As for modern Arabs or Arabised peoples often having a mediterranean appearance, that is due to intermixing that happened. Pure bedouins that retain more Natufian like ancestry do not look like that. They would be considered Caucasian by craniofacial measurements and hair type, but their complexion was much darker.
Its not surprising either, as even us Somalis who have a substantial amount of ancient East African ancestry produce mediterranean looking offspring within one generation of mixing with a European type ethnicity.