Board Thread:Warhammer 40k General Discussion/@comment-91.224.27.226-20131031140001/@comment-4851119-20140102121704

So what about Kurze? He was raised on a planet with effectively no natural light, so I'm guessing he's pale bone-white or something due to lack of pigment. However this would not be natural for him, it would happen over time (like a natural tan but in reverse), so most of the original Night Lords would be the same skin colour as he was at birth before losing any pigment. The later generation of Night Lords, who were recruited from Nostromo,

Back on the original topic: Maybe the II and XI Legions were early "prottypes" at creating "commando" Space Marines, but they were abysmal failures at covert ops, so they were discarded. Corax's and Alpharius' Legions were re-tasked for the covert ops job, and by happy coincidence their Primarchs were conveniently right for the job.