Back in the early 2000's John Deere won some arguments in court that became case law regarding their trade dress and colors, and the colors of the competitors weren't even close, and trim was a whole other color than yellow. I'm surprised that wasn't brought into the argument.
But because Lincoln offers special "packages" in other colors like Stainless or even possibly camo, would in turn discount their claim to trade dress I suppose. What do I know? I'm no lawyer.