dichromatism vs color blindness

dichromatism and color blindness both are nouns.

Word	Noun	Adjective	Verb	Adverb
dichromatism	Yes	No	No	No
color blindness	Yes	No	No	No

As nouns, color blindness is a hypernym of dichromatism; that is, color blindness is a word with a broader meaning than dichromatism:

dichromatism: a deficiency of color vision in which the person can match any given hue by mixing only two other wavelengths of light (as opposed to the three wavelengths needed by people with normal color vision)
color blindness: genetic inability to distinguish differences in hue

Other hypernyms of dichromatism include color vision deficiency, colour blindness, colour vision deficiency.

dichromatism (noun)	color blindness (noun)
a deficiency of color vision in which the person can match any given hue by mixing only two other wavelengths of light (as opposed to the three wavelengths needed by people with normal color vision)	genetic inability to distinguish differences in hue