This is what mine look like (I'm sorry, picture is a bit dark, but you get the general idea):
It's pretty straightforward and does't look too great on a single mini. But since this is
WHFB and you have ranks of models, I think it works fine.
So, here is how I paint mine:
Spray: Chaos Black
Whole Model: Rakarth Flesh
Scales: Khorne Red
Whole Model: Agrax Earthshade
Shield: Castellan Green
Shield: Athonian Camoshade
Shield: Underhive Ash
Shield: Athonian Camoshade
Scales: Agrax Earthshade
Weapon: Rhinox Hide
Stone: Mechanicus Standard Grey
Stone (Highlight): Dawnstone
Eyes: Incubi Darkness
Teeth: Praxety White
Teeth: Agrax Earthshade
Base: Lustrian Undergrowth
Base: Underhive Ash
Base: Athonian Camoshade
Base Trim: Steel Legion Drab
I personally don't like the blue look too much. It can look good when done properly, but I couldn't do it
However, I think your idea sounds really good.