neutral — not taking part or giving assistance in a dispute or war between others: a neutral nation during World War II.
colorless — Something that is colorless has no color at all.
colourless — Something that is colourless has no colour at all.
diatonic — of, relating to, or based upon any scale of five tones and two semitones produced by playing the white keys of a keyboard instrument, esp the natural major or minor scales forming the basis of the key system in Western music
