Contrasting as a term simply defines "difference", and when applied to color, difference of hue. These are great ways to easily draw attention to one thing or another by making the hue very different. So, for example, if we have a neutral beige wall with very neutral beige tone art on that wall, and we introduce a bright, vivid red toned art piece, that art piece will be the first one people see. This is because our human eyes love contrasts and are drawn to them.
Contrast exist in more than just our color world. It also exists in shapes, texture, and even our sense of taste. That one-in-a-million type experience could be considered a form of contrast in our memory.
However you use contrast, less is more. Keep it simple to ensure the effect will be very dramatic and purposeful.2013 Tracy Berry