In Blackwing Descent, they’re actually death knight-ish and glow bright blue, and similar in Blackwing Lair, they’re blue but just don’t glow.

… That’d clash so much with the lava D: I thought they were at least brown or something!

Well he /was/ undead in BWD.

Hey, I’ve already done a… dead, bug-cat, space elf! 


But yeah, it dooooes go with the lore. That said, nefarian’s not usually made of lava either. 
I’ll play around with the colours and see what works :>

Oh yeah, I’m just explaining why they were DK blue in BWD. Exactly who raised him still bothers me.