I imagine they are very close.
I found two other sources calling it Forrest service green.
And a quote off FTE:
"dnroberts , 02-03-2006 06:40 PM
Since I work for the Forest Service, I went out and looked at the paint number on a F250 and F450, it was W7603. Don't know if this will help or not. I wanted to see what the numbers were on the Chevy and Dodge we have, but since it is Friday, most people are off and I don't have the keys."