How would you paint something so that it is one color, but is a different color in the places where light is reflecting off of it? Like in BTAS, how Batman's cape, mask, gloves, & boots are always black, yet are blue where the light is reflecting off them.
you could start by trying to drybrush any RAISED areas of the figure with blue, after painting it entirely black. Say the Cape has raised ridges ,lightly paint the top portion of the ridge with the lighter color.