I bought these back in 4th edition, right when they came out. The models are amazing, both detail and design is excellent.
Their camo cloaks was painted Scorched Brown, followed by a liberal application of Graveyard Earth. Kommando Khaki for the top layer + highlights, followed by a dash of Flesh Wash in the cloak's creases. Then i applied Gryphonne Sepia over the entire cloak to smooth the rather course layering I had done, and to matt down the Flesh Wash. Finally, I touched up the highlights again, and the cloaks were done.
The undersuit was overbrushed dark grey, the face painted plainly with rather light highlights.
The blue gems are painted almost like described in the Eldar Codex: Necron Abyss, Enchanted Blue, Ice Blue (or rather something similar i mixed up).
All in all, I'm pleased with the result. They are clearly camouflaged, but at the same time interesting to behold.