tone down vs modify

tone down and modify both are verbs.

Word	Noun	Adjective	Verb	Adverb
tone down	No	No	Yes	No
modify	No	No	Yes	No

As verbs, modify is a hypernym of tone down; that is, modify is a word with a broader meaning than tone down:

Other hypernyms of tone down include alter, change.

tone down (verb)	modify (verb)
make less strong or intense; soften	make less severe or harsh or extreme
deaden (a sound or noise), especially by wrapping	add a modifier to a constituent
	cause to change; make different; cause a transformation