The second move element is that of a primary color jumping over a secondary color (orange, green, or violet). The primary color is subtracted from the secondary color, leaving the leftover pane in the middle space. Blue jumping over violet, for instance, leaves red. The middle pane must contain a secondary color that holds a component of the primary color jumping over it for the move to be legal; yellow, for instance, cannot jump over violet, since yellow is not a component of violet.
