Example : Hushed voices.
Muted trumpets.
A subdued whisper.
A quiet reprimand.

Synonyms : hushed, muted, quiet

Example : A little masterpiece of low-keyed eloquence.

Synonyms : low-key, low-keyed

Example : Children were subdued and silent.

Example : The moon cast soft shadows.
Soft pastel colors.
Subdued lighting.

Synonyms : soft

Example : A dim light beside the bed.
Subdued lights and soft music.

Synonyms : dim