Great thread. I saw the most beautifully done dark look on a girl not long ago. Part of the look I *think* you're talking about involves cooler even muddy colors rather than rich, warm colors. The girl had on some dark maybe faded black or dark dark gray jeans and layered slinky, spare top and sweater that were like 'old tattoo' colors - some dark muted ocean blue (OK, stormy ocean blue), some mushroom and dark taupe, gray, etc. Long dark hair, thin, stilettos, perfect look. In addition to the cool, sometimes muddy colors I'd add that things helping with the look are fluidity in the lines - raw edge hems or shawl-collar or simple stand-up minor drac collar - just think of the opposite of anything you'd typically get at J. Crew and you should be fine. Among celebs, it almost doesn't need to be said, but Angelina Jolie does the look well.
Minimal makeup should be needed but two things that can work are smoky eye designs and stains instead of lip glosses or colors - Vincent Longo's Neo Aura lipstain might be a good basic to start with.
Among clothing looks out there now, there are a lot of (very casual) screen print tees with dark, muted scrollwork and such that are good for the look.
Charcoal grey makes a softer alternative. (Btw, I believe our querent is an homme ...) 
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