What would be a perfect, or Ideal medium to replicate a picture that is from a comic book?

The picture from the comic book, is one where Spider Man is kissing Mary Jane while the background is a soft horizon. It's not the commonplace detailed kind where you see in action parts of the comics. It's soft, and feels like a calm green wave (that is, if you can imagine). I thought of Water Color, Oil Pastels, but if there are any professional views, or at least, one I can base my idea on, I'd definitely appreciate it.