US spellings

My remarkably good friend moshui finds himself quandarised caught on the horns of a quandary, and you know how uncomfortable that can be.

His copy-editor has recast his new fantasy novel in American spelling; which is not unreasonable on the face of it, its having an American publisher and hence inevitably a largely American audience. But Dan is a Brit to his boots, and his English is exceedingly British, and he's just not comfortable with this strange accent it's been pressed into.

But of course, being brighter than me, his first concern is sales. If he asked for the spellings to revert to English English, will potential readers be put off? He asks, and I don't know the answer; so I thought I'd ask you on his behalf. Go on over here and give him the benefit of your wisdom, for I have none.

(NB - it's a fantasy novel in a secondary world, sorta Chinese but not; no variety of English would be anybody's mother tongue, if that makes a difference...)

What colour is every-colour-but-black?

Just a thought, but does anybody know what colour I should set my laser colour printer to print, if I wanted to use equal amounts of all the colour cartridges and none of the black?

(Point being, obviously, that I get through lots of black and practically none of the colour; so I thought for drafts I could just print in whatever-colour-it-would-be that would use up those irritating colour cartridges of which I have a plethora, and so not need to replace the black of which I have a paucity...)