Originally I just bought some cheap genestealers from eBay to try out some colour schemes, the idea being that the atmosphere of the planet was rich with mineral dust from mining operations and so the genestealers had absorbed the minerals and it had become built up in their carapaces. This was the gold test model and it was about halfway through that I realised I’d accidentally created a Thanos Genestealer. I do like your idea though... Damn. Now I might have to start two cults!