somber
adj.serious, sad, or dark in color. You use this to describe a mood or a place that feels very quiet and not at all happy.
adj.characterised by a serious, grave, or gloomy mood; also used to describe dark or dull colours that lack brightness. Often used to describe the atmosphere of formal events or the emotional state of a person in mourning.
“The mood at the funeral was very somber.”
“He wore a somber black suit to the memorial service to show his respect for the family.”
“The hall was decorated in somber tones of grey and navy, reflecting the gravity of the diplomatic negotiations taking place within.”
Commonly used both to describe visual darkness and emotional gravity; often follows linking verbs like 'remain' or 'become'.
“There was a sombre mood in Oslo as Norwegians followed the comings and goings of the royal family.”