low-keyed vs subdued

low-keyed and subdued both are adjectives.

Word	Noun	Adjective	Verb	Adverb
low-keyed	No	Yes	No	No
subdued	No	Yes	No	No

As adjectives, low-keyed and subdued are synonyms defined as:

Other synonyms of low-keyed include low-key.

low-keyed (adjective)	subdued (adjective)
restrained in style or quality	lacking in light; not bright or harsh
	not brilliant or glaring
	restrained in style or quality
	in a softened tone
	quieted and brought under control