When someone says something is dark or bright, I always take age into consideration as well. Like it or not, the ability to hear high frequencies does diminish with age
I can hear the treble of the SR-007 MK1 extend up as far as I can hear (~18 Khz or there about).
Then there are headphones like the SR-404 that have a upper mid/low treble boost, that gives them the illusion of being well extended, but frankly I doubt it extended past 14 KHz (or the SRM-313 was just a really junk amp that severely limited FR extension).