I don’t think the brown spots in my picture is color fading. It is accumulation of tobacco tars.I see that, like most Peterson pipes with the green stain eventually do, your is starting to show the green stain fading to brown.
I do agree that the color is fading, and it is lighter than it used to be. I have seen pictures of others who have the same pipe, and their stain has faded, so that would be the eventual fate of mine as well. Mine survived so far, as I smoke slowly.