The whole model was sprayed black. The green areas were undercoated with Knarloc Green with a Catachan Green topping. Brown is Scorched Earth. If you're having trouble with camo try looking up some reference pictures of real tanks. You'll find that the disruption pattern will always cover straight lines and hard edges in an attempt to break up the vehicle outline. You shouldn't just paint splotches of colour in the middle of armour plates.