redness vs sanguine

redness and sanguine both are nouns.

Word	Noun	Adjective	Verb	Adverb
redness	Yes	No	No	No
sanguine	Yes	Yes	No	No

As nouns, sanguine is a hyponym of redness; that is, sanguine is a word with a more specific, narrower meaning than redness:

redness: red color or pigment; the chromatic color resembling the hue of blood
sanguine: a blood-red color

redness (noun)	sanguine (noun)
red color or pigment; the chromatic color resembling the hue of blood	chalk of a reddish-brown colour that resembles dried blood
a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat	a blood-red color

redness (adjective)	sanguine (adjective)
	inclined to a healthy reddish color often associated with outdoor life
	confidently optimistic and cheerful