Babylonians would have had a very wide range of skin tones, since Babylon was a central trading city for a very wide area. Unless this is pre-Hammurabi.

I have the same problem with this book as I do with any "our world exactly but with magic" books. That premise is not workable unless the magic is extremely small, contained, and hidden. Real gods written as Marduk is could not possibly be any of those things.

Also, I'm creeped out by "all Israel" wanting to sacrifice one of their own to Marduk, whom they could not possibly see as a legitimate god. There's some extreme antisemitism going on here under the fetishizing.