subduedness vs subdued

subduedness is a noun but subdued is not a noun.

Word	Noun	Adjective	Verb	Adverb
subduedness	Yes	No	No	No
subdued	No	Yes	No	No

subduedness (noun)	subdued (noun)
the property of lights or sounds that lack brilliance or are reduced in intensity
a disposition to be patient and long suffering

subduedness (adjective)	subdued (adjective)
	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