(Note that I’ve split this from the Confirmed Salamanders Successors
Curiously, the Salamanders didn’t have jet black skin and red eyes until after
the 3rd edition Index Astartes article. Neither version of the 3rd edition Index Astartes article mentions the eyes or skin, nor do the ‘Eavy Metal miniatures at that time portray such divergences. Instead, they were portrayed as having darker skin naturally (I recall “Afro-Caribbean” being used to describe them at that time, though I don’t recall if that was a term ever used in official publications or if it was just used at the B&C). For example, here’s a page from Codex: Armageddon
(3rd edition) showing a few Salamanders Space Marines without helmets:
This was a significant portrayal because it was the first time that an official Chapter had been shown with something other than (or in addition to) Caucasian Space Marines.
The shift to the jet black skin and red eyes came later. While it may have come earlier (i.e., late 3rd edition or some time during 4th edition, it definitely appeared in the 5th edition Codex: Space Marines
Born out of fire, the battle brothers of the Salamanders Chapter have jet-black skin and burning red eyes – a daemonic appearance brought about by a reaction between their unique genetics and the high levels of radiation on the Chapter Planet of Nocturne.
This was unfortunate in that it took the non-Caucasian Salamanders and made their dark skin the result of a genetic deviation (some might even call it a defect), removing an aspect of realistic diversity from the Space Marines. The beneficial side effect, however, was that it gave us a gene-seed defect/mutation that was acceptable (along with the opposite effect suffered by the Raven Guard, that of having skin that becomes pale over time). Regardless, the lore was worded in such a way that it made it possible for Successors of the Salamanders Legion to have similar eye and skin coloration (assuming the mutation was inherent to the genetic line and not a mutation/failure that the Salamanders Chapter
suffered later).The Horus Heresy Book II – Massacre
was published in 2008 and cemented the origin of the genetic deviation to the Legion’s
genetic nature, making it likely that any future Successors of the XVIIIth Legion might suffer similar effects from exposure to high levels of radiation (with the exceptions of those that might have suffered further mutations or lost that organ).
This variant gene-seed, however, also has some unusual outward side effects, the first of which, noticeable even in the first Terran members of the XVIIIth’s intake, was a much-remarked ‘ember-like’ bioluminescence to their eyes and a tendency for skin pigmentation to permanently darken in response to prolonged exposure to high levels of potentially harmful radiation as part of their biological defence mechanism, often adopting an unnatural granite-like or obsidian quality with sufficient exposure.