tastefulness vs elegance

tastefulness and elegance both are nouns.

Word	Noun	Adjective	Verb	Adverb
tastefulness	Yes	No	No	No
elegance	Yes	No	No	No

As nouns, elegance is a hypernym of tastefulness; that is, elegance is a word with a broader meaning than tastefulness:

tastefulness (noun)	elegance (noun)
elegance indicated by good taste	a refined quality of gracefulness and good taste
	a quality of neatness and ingenious simplicity in the solution of a problem (especially in science or mathematics)