I feel you here, moose, I really do: every time I see the WoRGBs I've thought the same thing.
But my question is: on a WoX keyboard (think of X as an arbitrary, probably dark, color), what is going to look more 'off':
WoRGB
or
BoRGB?
I truly don't know because I don't have a dark set of GMKs with White legends, nor a set of WoRGBs. I've seen a bunch of pics, though...
I can't help but think that the only way that WoRGB could be improved is to darken all three shades of RGB a bit. Make them less bright and this would probably work better.
Because R, G and B are primary I'm thinking they could be darkened quite a bit beyond what we see these days with no loss of contrast.