Wittgenstein on color, remark #9

Even if green is not an intermediary color between yellow and blue, couldn't there be people for whom there is bluish-yellow, reddish-green? I.e. people whose color concepts deviate from ours &emdash; because, after all, the color concepts of color-blind people too deviate from those of normal people, and not every deviation from the norm must be a blindness, a defect.