Here's a sketch I did onto black card stock. I love the way the colors are vibrant against the background and the white outline highlights and creates even more contrast. Using the black paper is a fun challenge because it can be used as the shading if I don't add color. It is called "negative" space or image and learning to use it (by NOT adding color) is harder than it looks for me. But, I love the look of it.
Here's a digitally altered background that still keeps the black, but adds a few more layers and textures. I'm not sure, I think I prefer the solid black background, but I enjoyed trying something new also.