might I suggest some colors? I would use flat black on the coat and arms to make it look more like natural leather. then use dark browns, that are almost black, for the tunic and under robes. Testors acrylic has a brown I realy like that is titled "leather". Mixing it with a little flat black makes an EXCELENT dark brown leather look. go even farther by dry brushing the "leather" areas with a dark flat great to give it some depth, but not too much....
and for the small parts of armor, a dark red or dark blue maybe? depending on your favorite colors... heck even a dark deep green would be good. And I would also use semi-gloss or gloss paint for the armor, to give it that distinction of looking metal.