Call of Duty: Infinite Warfare
It appears as a gold coloured finish styled towards a paint splatter.
It is unlocked after achieving 100 headshots with Assault Rifles, Light Machine Guns, Sniper Rifles and Pistols, 100 hipfire kills with Shotguns and Submachine Guns or for destroying 32000 points worth of scorestreaks with Launchers.
Call of Duty: Black Ops 4
In Call of Duty: Black Ops 4, the camouflage appears as a blue and purple abstract paint splatter.