Just as I tried to subtly differentiate my Nurgle marked marines through excess rust and corrosion, I tried to use paint to help separate these guys as marked by Khorne. The first step to differentiating them was to give them a brighter bronze base than my other figures. This bronze still got the same patina wash as the regular troops, but I think starting from a brighter spot makes them that tiny bit shinier. I've also minimized the hazard striping, isolating it to the left shoulder pad. Because I kept the same amount of black on the weapons and armor plating, this lack of striping has the added effect of making the unit a little more dark and sinister as a whole.
I'm not 100% happy with the flat black, but all of my attempts to make it pop - red glazing, edge highlighting, patchwork of skulls - only made the weapons look worse. I'll let the ideas percolate a bit and see if I come up with something else. If I do, great! If I don't... these guys are considered [i]done[/i].
Now, if you'll excuse me, I need to go sculpt some Dreadball turtles.