The color was basically a light olive drab. The color actually varied between manufacturers. Here are a couple of photos of reproduction uniforms for renactors.
Here is the website they came from that may give you more info.
http://www.wwiiimpressions.com/
Gino P. Quintiliani - Field Artillery - The KING of BATTLE!!!
Check out my Gallery: https://app.photobucket.com/u/HeavyArty
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell