monochromatism vs monochromacy

monochromatism and monochromacy both are nouns.

Word	Noun	Adjective	Verb	Adverb
monochromatism	Yes	No	No	No
monochromacy	Yes	No	No	No

As nouns, monochromatism and monochromacy are synonyms defined as:

monochromatism and monochromacy: complete color blindness; colors can be differentiated only on the basis of brightness

Other synonyms of monochromatism include monochromasy, monochromatic vision, monochromia.

monochromatism (noun)	monochromacy (noun)
complete color blindness; colors can be differentiated only on the basis of brightness	complete color blindness; colors can be differentiated only on the basis of brightness