achromaticity vs achromatism

achromaticity and achromatism both are nouns.

Word	Noun	Adjective	Verb	Adverb
achromaticity	Yes	No	No	No
achromatism	Yes	No	No	No

As nouns, achromaticity and achromatism are synonyms defined as:

achromaticity and achromatism: the visual property of being without chromatic color

Other synonyms of achromaticity include colorlessness, colourlessness.

achromaticity (noun)	achromatism (noun)
the visual property of being without chromatic color	the visual property of being without chromatic color