The few times I was stunned by beautiful color schemes on characters in live games or on video, they definitely belonged to male players. I can even name a few, that's how stunned I was. IAMxSHADRACH has this amazing geth trooper with iridescent shades of blue and green flowing over a metallic background. Then there's the succession of Rustinman's characters, all painted in reds, oranges and yellows so as to simulate rust (with varying degrees of success, but this looks utterly awesome under tech armor). I just love Chealec's pink krogan (soldier? sentinel? not sure); might be it was intended to be violet, but it comes across as pink and the adorableness of it is in exquisite contrast to what a deadly kit it is in such capable hands. Also I must say I'm growing on simple schemes, like what one can see on ex-Clusum's asari and turian characters (and the black fury) - unassuming, but very effective.
At various points I had a mind to set up some color scheme for my characters, like a sort of hallmark or what have you - but I don't have the patience for it. Most my painting happens while waiting for friends to join my lobby and often ends up sloppy. 
I suppose this is even farther from the thread subject than physics in the thunderdome, but I felt like sharing.