he won't be commenting further as its kinda useless
This is sort of the route I was taking, actually. I was satisfied with that. But the question was asked, again, so I made something up.
The issue at hand is that while yes, there are things like the Dyers Guild for the dwarfs, and places known for it, the sheer breadth of the Empire and the uniforms and the Cults make things a bit funky, a lot of the time, yes? Shallyans almost always are dressed in whites and pale blues and a couple of others. The ENTIRE Cult of Morr, which is spread throughout the entire Old World, from acolytes to laymen to priests all wear head to toe black. All the militias and armies of Stirland have major black features, and Ostland has significant amounts of black as well. It's noted that purple is specifically hard, which is why the actual amount of purple in Ostermark uniforms varies.
I just uh...kinda of didn't want to think too hard about it, because GW clearly didn't, and sometimes I'm fine with filling in the worldbuilding gaps, yes. But you guys gotta realize, goddang there are a lotta them holes and gaps sometimes, you know? And I am but one man with a shovel and some dirt, not a full on cement mixer or blacktop maintenance crew. Bad of me, sure, dye is a major trade good in this era, obviously, I was just kinda...hoping to not have to think to hard on it when there's the everything else going on in-quest. I uh, I'll try to come up with more concrete dye stuff soon, I guess. Sorry.
The existence of tannis in plant life is a real thing, and with a bit of iron rust and some water is a real way to get black dye, by the way. So, you know, maybe it'll be stuff like that? Some kinda...purple dye giving snails that live in the swamps of Ostermark...I'll need to think a bit more on other things too.
That's not exactly it. Tome of Salvation says there are some extremists within the order that do what you describe, but the normal part of the Order just teaches that there's gonna be an Evernacht and that Winter is training for it. It's not an entire sanctioned order of silo-burners.
The Tome of Salvation is also technically 'current' to the year 2522, not 2342. The Order of the Winter Throne was founded centuries before that point, and was only controversially taken into the Cult properly in 1975...specifically by the original founder's grandson who had managed to become Ar-Ulric by that point. The Celibate Restrictions enacted upon the Cult show that the Cult itself is not somehow magically immune from intrigues and political maneuvering which is not necessarily beneficial to the greater Cult. The Era of Three Emperors was a dire time for all, and I do not find it inconceivable that in such chaos, many were able to think that the Evernacht is extremely eminent, therefore leading to more doing their business here and there. Consider also that I recently mentioned Olric, a Norscan savage God with noted similarities to Ulric, only being far more bloodthirsty, savage, and bestial as befitting a God that the Norscans would worship. The nature of the actual Throne of the Snow King within Norsca is deliberately unclear, much like the Secret of the Dark Maiden with regards to the Cult of Myrmidia. In the time of Magnus the Pious, all the Cults were revitalized, the Empire was rejoined, and the anarchy died out, which restricted several normal behaviors - such as the constant political infighting and intrigue messing around.
The whole small blurb with Magnus being served by the former top Khaine assassin in the entire Empire as a maid, having rejected Khaine, and all that? Was after the cultists sent her after Magnus specifically because of such major anarchy reduction.
In the modern times, sure, the extremists are the ones who do things on the fringes, while the majority remain as ascetics in their isolated monasteries preparing for Evernacht.
But Cults and even just orders somewhat related to the Cults or religious organizations in general can change radically not just in the span of a few centuries, but of a few years. A single generation. Etc. And can do things wholly out of stated source text, on occasion, because the world itself is not static, and things can change. The Holders of the Shore. The Knights of Margritta.
The Yellow Fang. The radically altered Cult of Morr.
Slaaneshi Vylrmarist. The now
plural Flames of Ulric.
The Reforged Hammers. A more developed and active Quinsberry Lodge. And so on.
It's more the species best adapted to its environment - and Bretonnia seems to have found a pretty good adaptation and stuck to it so far. I imagine it's kinda like crocodiles IRL, which haven't changed much in the past hundred million years (or so the archaeologists say).
