I think the lighting on this really hurt the shot. The colors look a little dull overall, I think because the lighting is just a bit harsh and also perhaps becasue of white background which sort of overpowers the image with brightness. This same shot with softer lighting on a black or gray BG would be a lot more visually impacting.
Your photo does indeed match the username. I wonder how this would look on a black background as I think maybe the white one washes out the colros of the skittles themselves.