Saving Private Ryan

The movie I chose to use is Saving Private Ryan.
My question is: How does the film maker convey evil or darkness?
In Saving private Ryan, Steven speilberg really brings forth darkness in a few ways. The first I noticed was the always overcast skies and the overall lack of brightness throughout the movie. Even when the sky was sunny the scenes still felt dark. I think he made it this way to always make the scenes have a depressing somber tone. Another way darkness was brought forward was through the shooting and the killing scenes. This movie definitely had a lot of that because he wanted to remind us of the realities of World War 2.