-red and black (coppering over flammable paint, carbon in outer v/crease, cranberry somewhere in there to blend lines, something like shroom to highlight)
-silver/white and black (nylon and carbon look good together, as do crystal avalance and carbon)
-yellow and brown (i did a chrome yellow, rule and embark look recently and i loved it. i used rule in the crease with embark defined with the 219 brush, CY on lid and it was summery yet bold)
-blue/purples look awesome...zonk blue on lid, with nocturnelle/shadowy lady in outer v/crease area, maybe even beautiful iris in the tearduct, super hot!)
-for golds, colors like juiced or soft brown complement the crease nicely