But if part were in the unbra, this part should appear reddish.
Only if the moon is fully within the umbra does it appear red. That's the point of my modification. If even a tiny part of the Sun peaks around the Earth it floods the moon with so much light the small amount of red cast into the shadow is insignificant, and one sees a gray cum black moon.
For the Moon to be seen as red the residents of the Levant would have had to have been observing a total lunar eclipse or some other, unrelated event. And even at that they'd also need time for their eyes to be dark adjusted for the red tinge to register.
A Moon low on the horizon can appear red with non dark-adjusted eyes because the full amount of light reflected off of the Moon is being filtered by the atmosphere as it travels from the Moon to the observer. There's a whole heck of a lot more red light in the light reflected off of the Moon then there is in the dribble that makes it round the Earth to tinge the umbra. And We're no done yet, there are further losses as it bounces back and is filtered by the atmosphere again.
Another explanation for the red Moon will have to be found. My pet is that high drama is a Bible writers groove.
It's not the man that knows the most that has the most to say.
Anon