Works of art that express a sad/mournful tone might depict grieving characters and/or scenes of death, destitution, or profound loss. Beyond representation, stylistic elements such as grays and dark values, very muted colors, and perhaps a splotchy or stumbled texture might contribute to a sad/mournful feeling.
An artist might impart a sad/mournful tone to a piece due to his or her own emotional state, or the artist might choose to evoke this tone as a reflection of the characters being portrayed. A sad/mournful tone might also be adopted to suit a piece meant for a setting or purpose that demands an expression of sorrow.
Featured: Hunger by Käthe Kollwitz.