This depends on which of Poe's poems you are referring to. All of the imagery in Poe's poems are dark. Consider the poem The Raven. The poem begins with,
Once upon a midnight dreary, while I pondered, weak and weary
“midnight dreary....That I scarce was sure I heard you”—here I opened wide the door Darkness there and nothing more.
This is a dark beginning but the imagery continues to get darker. The raven himself holds dark imagery.