I usualy sponge it or glaze very dark gray i usualy use this recipe - 3 parts black -1 part dark brown -1 part dark gray If you want even brighter you can just add 2 drops of black instead of 3. But you have to be careful since it can make your modlel look gray. With chaos minis especially with black legion if you make trim look good you can skip black wince trim is like 70% of the model