Can I have too many differences in my design?

There are no limits to how many differences you can have in your art. It is important, however, to remember that more is not necessarily better. It might be more powerful to focus on one or two differences if you are particularly interested in showing those and reducing the extraneous differences to make what’s left more potent and noticeable. For example, if you want to show differences of color it might not be helpful to show additional differences of texture, shape, and value. It is important to be clear about what you are interested in showing to the viewer. See "What is Dominance?"