Citadel paints used to paint this, took me awhile here is a little background on the spektrs: spektrs love up to there name. They are stealthy ghosts capable of the most astonishing feats of infiltration. When wet work requires surgical precision, when the situation is to delicate to admit a single mistake, they call in these guy,Tunguska uses them primarily for industrial espionage or extraction ops, for their own benefit or as an expensive service to third parties, equipped with the most sophisticated cloaking and camouflage technology money can buy, they can walk past most surveillance systems undetected. Hence the rumour that they are not trained for infiltration, but trained to disappear into thin air.