greenness vs spectral colour

greenness and spectral colour both are nouns.

Word	Noun	Adjective	Verb	Adverb
greenness	Yes	No	No	No
spectral colour	Yes	No	No	No

As nouns, spectral colour is a hypernym of greenness; that is, spectral colour is a word with a broader meaning than greenness:

Other hypernyms of greenness include chromatic color, chromatic colour, spectral color.

greenness (noun)	spectral colour (noun)
green color or pigment; resembling the color of growing grass	a color that has hue
the lush appearance of flourishing vegetation
the state of not being ripe