Don't judge by the cover!

[TWErvin2]

I noticed this too! It does make you wonder if they even bother reading it! I think they simply want to portray him as dark, which is missing the point really.

Covers aren't necessarily created to be an accurate reproduction of a novel's contents. An actual scene from the story, or the exact color of clothing isn't always important. In the case of the image on the cover The Picture of Dorian Gray in question would be an example (see above posts).

Consider the cover to be a marketing device or tool, one to get attention and to give an initial 'feel' or suggestion of what the novel is about to a potential reader.