The GraviTrax Color Swap element changes the color of the balls as they pass through. If a ball rolls into the Color Swap, the color of the ball changes as if by magic when it leaves the element. The illusion can be created in two ways. Firstly, the element can be loaded with a ball at the start or the Color Swap can be built into the track. Combined with any GraviTrax starter set, the Color Swap adds a whole new dimension to the track.