>>96471486
They became renegades which are broadly under the umbrella of Black Shields. Black Shield originally is a term for a marine that has eschewed their original chapter AND changed/censored it. But the Ashen Claws weren't always renegade. Plus the pale Nomads asl exist, they stayed loyal and later became the Carchardodons. They're not black shields are they? So once again, there can be a chapter that is within the legion that is divergent. They can stay loyal, become a traitor, or go renegade as time goes on. Anons chapter could easily become renegade later, or have been so far out that they retained their pre Primarch iconography and died off in the heresy before they had a chance to turn.

>>96471529
So I ask again, we've catalogued all existing chapters and their visual identity across every legion? Thus there can't be a blue flame salamanders company recruited from a world that had high metal content that burned blue in places? Becuase every single salamander chapter is visually catalogued?

The existence of the loyal Pale Nomads is proof enough that a chapter can be visually divergent, pre primarch, and stay loyal. They used stealth, recon, etc well before Corax showed up and were the nicknamed the "Hidden Hand". Quite literally RG tactics, but without the noble bright leash Corax out on his legion. Despite being exiled later on by Corax they stayed loyal to the imperium and were not Black shields. Salamanders trait is just being tough from their geneseed, so it's not like you need special training for that.