The armor was a bit of a challenge on this guy. While I feel pretty confident painting white, I'm still very apprehensive when it comes to painting black. As with white I want to stay way from the neutral black and grey mix. I've done some brown-blacks but this time around I wanted to do more of a blue-black. I guess the standard approach would be to start with a black, mix in some dark blue (like a Prussian blue), and then use some skin tones to create the highlights. However I took a bit of inspiration from the Sons of Horus and picked a sea green shade instead of a dark blue. From the Reaper line the paints I choose were black, marine teal, and tanned skin.
Of course I don't use pure marine teal or tanned skin. I work from pure black to about a 3 parts black to 1 part teal. Enough so you clearly can see the difference from pure black, but not too light. More of a dark to medium grey. I then take the black/teal mix and start to add tanned skin. Depending on how light you want it maybe you get to 2 parts black/teal to one part skin. These are just rough estimates. Mix in a little bit at a time and see how it goes.
The idea for the brown black is the same, you just switch out a dark brown for the blue/teal.
The shoulder armor is done in read to match the Justaerin color scheme. I like to go with a bit of a purple tone in the shadows, so I started with burgundy wine and then violet red before I got into one of the brighter red shades. The red leather strips still need a lot of work but I think the little bit of color there helps.