Works of art that express a serious/solemn tone might depict characters that are in straightforward interaction with other characters or with the viewer. Beyond representation, stylistic elements such as slightly muted colors, controlled edges, and careful rendering of form might lend a serious/solemn tone.
An artist might impart a serious/solemn 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 serious/solemn tone might also be adopted to suit a piece meant for a setting or purpose that demands directness.
Featured: Self-Portrait by Rembrandt Van Rijin.