This is how I modelled and painted these berserkers: They're kit bashed from a bunch of different kits: khorne berserkers, chaos space marines, ultramarines and blood angels kits, fantasy chaos kits (particularly the chaos warriors mounted chosen kit, an awesome little box for bits). The bases are various skeleton kits from fantasy.
The red is 4-6 layers of watered down blood red painted on top of each other. They get cleaned up with black paint, detailed with dwarf bronze, boltgun metal, and snake bite leather, then shaded with badab black and highlighted with blazing orange. The bases are bleached bone on top of scorched brown, with the weapons done in boltgun metal.
I used so many blood angels bits because the models were too cool to pass up, and also because the codex looked pretty good to me. But I wanted the background and modelling to give at least some kind of rationale for why a bunch of berserkers would be using the blood angels codex. It's like saying: "ok this is a counts as army, but I paid my dues. Sort of.) I also read Soul Hunter and was really struck by his depiction of the Night Lords as having alot of logistical problems. I figured these guys, like Dembski-Bowden's Night Lords, just dont have the labor and supplies that they need to do everything, so alot of the symbols they had on their armor when they went renegade are still there. They just dont have the resources to deface it all.