Jas260I do a lot of DIY projects with wood. Purple Heart is beautiful, and exotic, but also incredibly easy to mess up. Purple Heart is known to splinter when routing, chip when planing (reducing thickness), or burn when sawing. I trust Fostex, though.
madwolfaEven if kept covered or in a closet, away from UV, they will still darken from oxidation, even through a polyurethane coating. See the second to last paragraph of:
http://hobbithouseinc.com/personal/woodpics/purpleheart.htm
Will mentioned in his first comment (page 1), however, that these would be died. Will the die maintain the purple appearance in the pictures?
MeringoWill said it's gonna be subtle and he's the one selling it, if he wanted he would say it's a completely different pair of headphones that you should own along with the mahogany TH-X00, but he didn't.
madwolfaWell wood does expand and contract with weather. It's humid most part of the year where I live and my mahogany bodied guitars fare better than my one cedar one. The cedar one actually bows out due to the humidity. Not sure about denser woods. Rosewood and teak withstand humidity very well. I'm real wary when it comes to wood.
BuckbrickPurpleheart is extremely durable and water-resistant wood. Other than color shift due to UV and being an ass to work with, it's pretty much invincible.