A pretty simple paint job. Base coat in black, then a heavy drybrush of Codex Gray, then a light drybrush of Mithral Silver to give them an ethereal look. The eye sockets are are dotted with Vile Green to make them look eerie. I used some Reaper metallics (Fire Glow, Brass, and Green Steel, respectively) to paint a rune on their heads and do a light drybrush to make them easier to identify in play (so I can say "the greenish one" instead of "the one near the fighter ... no, the other one"). Their bases are just little spikes and so it was hard to get them to balance in a proper slotted base, so I made bases out of Sculpey, painted them black, and added gravel flocking.