I do like the idea of a complete GH classic colorscheme charcoal, orange and white set.
I have talked with sleabo a few times about various potential buys, and unless I am mistaken the 100 MOQ on modifiers needed the same base color, but could split up the infill colors to whatever since it is a secondary process. If that's the case I think it would be easier to settle on something neutral like dark grey and people can do white, orange, pink or whatever they may prefer for thier legend infill.
I was actually thinking of trying a buy with them soon for a few various small sets like CMYK mods (C M and Y on black keys, and set with reveresed caps lock and control positions on beige. But the high prices due to them being UK based and high MOQ for the keys I have been pretty hesitant.