I can relate to your story.
I live in Illinois also and about 4 yrs ago my buddy had a Game Warden walk up on him opening day deer season wearing ALL dark green and NO orange.
I thought this was weird too, but didn't want to question him since he was checking properties for baiting as the game warden helicopter had spotted a pile of corn on neighboring ground.
The guy was ALL business and had no sense of humor--"just the facts",man.
He checked our tags/licenses,asked a few questions and left.

Mark