Plaguebearers: I like to give mine that sickly green-rotted look. I haven't painted any in a while, but did a basecoat of Bleached Bone. Then a thick wash of Green Ink (of course Thrakka Green wash will be used now). Then I just heaped on some layers of drybrushes; Bleached Bone, Rotting Flesh, Pallid Flesh. Then detailed the tounges and guts in Purples and Blues and gave the eyes a nice dot of red to make it stand out. The 'blades' were Boltgun Metal and washed with Red Ink.
Of course, I painted those up 2 years ago, now there's Foundation Paints and the new Washes, you can get some pretty good results in an evenings paint session.
Hope that helps, Good Luck!