brown vs chromatic color

brown and chromatic color both are nouns.

Word	Noun	Adjective	Verb	Adverb
brown	Yes	Yes	Yes	No
chromatic color	Yes	No	No	No

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

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

brown (noun)	chromatic color (noun)
an orange of low brightness and saturation	a color that has hue

brown (adjective)	chromatic color (adjective)
(of skin) deeply suntanned
of a color similar to that of wood or earth

brown (verb)	chromatic color (verb)
fry in a pan until it changes color
make brown in color