If it would help at all, I posted a picture of an airborne trooper in 120 mm scale on this forum about a month ago. The thread was entitled "101st Airborne trooper" and is on about page 3 or 4 of this forum. I am very confidant that the colours of the uniform, which appear to be almost tan, are correct for the period of the Normandy landings.
There are a few military re-enactor sites that feature American airborne uniforms and these sites provide a ready reference for any modeler needing to get the colours just right. Try this one;
www.atthefront.com
I was just there and they feature a couple of examples of U.S. airborne packages for sale to historical re-enactors, and you've got to know that these guys go to great lengths to get things like colour correct. Good luck.