B. metallicolor is in the Petermannia section, and is native to Padawan, Sarawak, Borneo. It resembles B. nagaensis in the iridescence, but the flowers differ. Like B. darthvaderiana, metallicolor is found in low elevation dipterocarp forest. It is a rather small species, growing to just under 12 inches, but it often stays smaller. The leaves are strongly iridescent and can appear blue, teal, green, and even purple.
The plant below seems to be doing well, but also has some sort of fungal infection that I have not yet dealt with. I plan to treat it with potassium bicarbonate after it finishes flowering. The abaxial surface is a beautiful reddish-bronze, with new growth a similar color. The plant below has produced one female flower so far, but unfortunately even despite repeatedly pollinating it by hand, it yielded not a single seed! It is forming another, which I hope will prove more fruitful.
The original description can be found here, along with descriptions for ten other species.