In my opinion, the glow of the red moon is red. Visibility under only moonlight (which would be rare since there would always be stars and planets to lend their light, too) would resemble that under sodium vapor lamps - doing strange things to colors. (On the other hand, I wouldn't vouch for the Gloranthan colors to add up or break down like our colors do, so the opposite color of the moonglow may be something mythically more appropriate than green.)
The silver shadow experiences silver light because it is magically part of the surface of the Red Moon, and much closer to the stars - also IMO.
>
> I hope I'm doing this right - never really posted to this list before
> despite having been running Gloranthan games since the early 80's...
>
> This just came up in my game. I described the night as being bathed in
> red moonlight and one of my players disagreed. They pointed out that the
> region directly under the moon is SILVER shadow and that there are a
> whole sequence of silver related concepts relating to the moon.
>
> Obviously white/silver light is better than red when it comes to seeing
> at night so is it true that while the moon appears red it casts a white
> light? And if not, why all the silver references?
>