The Salamanders. The 18th Legion. The forge lords. The salamanders are master craftesmen, and have a talent at crafting relic worthy weapons and armor. 9 of these are forged by the Primarch himself, hidden throughout the universe, to stop corrupt people from using them. The Salamanders are from the world Nocturne. It is a very volcanic world with hundreds of volcanoes scattered across its surface. These volcanoes are used to forge the Legion's tools of war. They have an addiction to close quarters combat with flamers and melta guns. Their weapons are all works of art, and each marine must take care of his own gear, to prove he is a craftsman. Their skin and eyes are what seperate them the most from other legions. Their eyes are fire-blood red and their skin is a very dark and deep brown. They fight for the Emperor, and his people.

Salamanders page on Lexicanum wiki
This skin is from The Heresy Era Skin Project