ring of color vs areola

ring of color and areola both are nouns.

Word	Noun	Adjective	Verb	Adverb
ring of color	Yes	No	No	No
areola	Yes	No	No	No

As nouns, ring of color and areola are synonyms defined as:

ring of color and areola: small circular area such as that around the human nipple or an inflamed area around a pimple or insect bite

ring of color (noun)	areola (noun)
small circular area such as that around the human nipple or an inflamed area around a pimple or insect bite	small circular area such as that around the human nipple or an inflamed area around a pimple or insect bite
	small space in a tissue or body part such as the area between veins on a leaf or an insect's wing