The mood of both the passage and the painting can be described as somber. In the passage from "Romeo and Juliet," the language expresses despair and urgency in the face of death and tragedy, particularly with the references to "death" and "unnatural sleep." This somber tone is reinforced by Friar Lawrence's insistence that they must leave quickly due to the ominous situation.
Similarly, if the painting you are referring to depicts themes of death, loss, or despair, it would align with this somber mood. Therefore, the correct response is somber.