Analyzing Diction for Emotional Tone

In the following excerpt from a fictional narrative, the author employs distinct diction to convey the emotional landscape of the protagonist during a moment of introspection:

"As the sun dipped below the horizon, a cascade of hues engulfed the sky—fiery crimson intertwined with gentle lavender, painting a masterpiece that mirrored the turmoil within her heart. In that fleeting twilight, shadows whispered secrets of sorrow, each one a reminder that joy is often a mere illusion, a fleeting wisp in the tempest of existence."

Based on the author's language choices, which word best captures the overall tone of the excerpt?