According to the below link Padauk does turn brown over time. Personally, I like the aged Cherry color or woods in the rosewood family. I was going to purchase the Omni with Ormosia Henryi (this is also know as yellow rosewood). Again, color & appearance are one thing the other is that woods do sound different and that is very important as well.
http://www.wood-database.com/wood-articles/top-ten-overrated-woods/
None of this is a surprise to woodworkers. It's well known that all woods darken somewhat with exposure to UV radiation in sunlight, due to oxidation of chemicals in the wood's structure. The effect varies quite a bit by species of wood (even w/in the same board of the same species); and is affected by handling & storage, ie, keep your headphones out in sunlight vs a darkened room and the process will be accelerated.
I also point out the hyped, inaccurate tone of content on that website--not a good source. For example, whoever wrote it trashes oak ("This wood is everywhere."). Yes, and those annoyingly beautiful trees are
everywhere! (the writer annoys me). I challenge him/her to find any more beautiful wood than quarter-sawn white oak. Fumed & waxed, it's the hallmark of "craftsman" furniture.
Anyway: focusing too much on darkening misses the larger points that wood is organic & has a mind of its own (changing in subtle ways, both in color and dimension, long after being finished); and it offers incomparable tonal advantages over other materials. In fact, just look at the Omni line, a veritable "tonal palette" of wood. Looks are hardly the only thing happening there.
Zach obviously knows his craft. He must have chosen padauk as the upgrade for these 2 new products based on a combination of sound, looks, continuing availability/quality & workability. There's certainly precedent for this: padauk is commonly used as as a tone wood for instrument construction in Africa and other places where it grows.
Regarding color--the finished headphones do look fairly dark--I would only say, if Zach is coloring/staining the wood at all before sealing (for example, to "even out" the grain) he may want to back off that just a big for longest/best results of grain appearance. But again, he knows his craft; this is mere 2nd guessing...I haven't done many dozens of test stains/seals, and he no doubt has.
Having said all this, I admit to having my own "ZMF wood fantasy," like many on this string:
1. Suddenly, Zach offers to make Atticus HP's in buyers' choice of woods (for a limited time). Hey, it's a fantasy!
2. I immediately jump off the fence (where I seem to live) and order my Atticus in ormosia henryi, the wood I've been jonesing for in Omni's because IMO it has the perfect blend of light brown + a dash of red & pink, and the grain is striking, yet subtle. This wood makes me break out in a cold sweat.
3. Best of all, in the application of the Atticus, the relatively small pores + density/hardness of ormosia Henryi (= speed) may well have synergy with the inherently romantic voicing of this headphone (or so my fantasy goes).
(thanks for listening)