These are two of my favourite pipes and a few words on them. Have a gander.
Sultan: Acquired in January 2012
Lattice: Acquired in August 2013
It's fairly obvious which one has been smoked more. Aesthetically, I find them both equally gorgeous, albeit in different ways. However, I prefer the #smoking mechanics of the lattice over the sultan; the draw on the latter, while not problematic, is not entirely satisfactory.
I've put off fixing that for quite some time, but I got around to it today. So perhaps the sultan will experience a furnace in his skull a lot more often henceforth.
Colouration tends to occur at the stem a good while before any other area is affected, and it's rather evident in the sultan's case. The pipes' material, Meerschaum, is extremely porous and lightweight, meaning that it absorbs moisture and oils from burning tobacco, and exhibits this, as it were, at the surface.
As a side note, I'm not one to smoke these with a glove, nor would I wrap them in linen for a decade. Clean hands are all that's necessary for me, and if colouring varies across each #pipe as a result of where I've touched, so be it.