It's generally agreed that Jews of that time and place would have looked more like people of that place look today. In other words, olive complexion, dark curly hair, brown eyes. There could certainly be some variation from that, but not Christian Bale-like variation. Particularly since there was no sunscreen at the time, so you'd expect people to have had their skin darkened by the sun.

It's also important to understand the context of this issue. There has been a trend in European art of the past 200 years or so to depict early Christians like Jesus and the Apostles, as well as acclaimed Old Testament figures, as very northern European looking. At the same time, there has been a trend to depict villainous New Testament Figures (Judas, Pontius Pilate, Salome, etc.) and very Jewish-identified Old Testament figures as stereotypically Jewish looking (olive complexion, big nose, curly dark hair, sinister beady eyes, occasionally horns). So casting a very northern European-looking actor as Moses is reminiscent of those antisemitic depictions. It's also likely very telling of who gets ahead in Hollywood, that there aren't a lot of swarthy middle-eastern-looking people to star in the movie. It's interesting that several of the stars are Indian, or part Indian. In India, paler Indians tend to be successful in film, and can then get an occasional role in Hollywood films by playing the more rare roles for darker-skinned people in Hollywood, though they might not be looked at for just any old rom com or drama--only the ones that absolutely require a darker-skinned person, like Ben Kingsley, who has one Indian parent and one English parent, and who gets roles like Gandhi and like Jewish men in Schindler's List, Mrs. Harris, Anne Frank: The Whole Story, and Moses. In other words, while there are a lot of Jewish actors and actresses, very few are stereotypically Jewish-looking because that is not a look that is rewarded. Then, the most European-looking Indians get jobs in India, and can also get jobs occasionally in American flicks for being the most swarthy European-looking people.

If you're interested in this topic, here's an article that is peripherally related: http://www.nybooks.com/blogs/gallery/2014/nov/14/invention-jewish-nose/