tint vs undertone

tint and undertone both are nouns.

Word	Noun	Adjective	Verb	Adverb
tint	Yes	No	Yes	No
undertone	Yes	No	No	No

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

Other hyponyms of tint include mellowness, richness, tinge.

tint (noun)	undertone (noun)
a quality of a given color that differs slightly from another color	a pale or subdued color
a just detectable amount	a subdued emotional quality underlying an utterance; implicit meaning
a dye for coloring the hair	a quiet or hushed tone of voice

tint (verb)	undertone (verb)
color lightly