greenness vs viridity

greenness and viridity both are nouns.

Word	Noun	Adjective	Verb	Adverb
greenness	Yes	No	No	No
viridity	Yes	No	No	No

As nouns, greenness and viridity are synonyms defined as:

greenness and viridity: green color or pigment; resembling the color of growing grass

Other synonyms of greenness include green.

greenness (noun)	viridity (noun)
green color or pigment; resembling the color of growing grass	green color or pigment; resembling the color of growing grass
the lush appearance of flourishing vegetation
the state of not being ripe