It is easy to adjust which variable and which axis is used to assign colors to the lines.  By default, the color variable is placed on the axis at far left, indicated by the radio buttons above the axis.  The other radio buttons in that set are used as an interface to assign variables to positions on other representation forms in the larger system (in particular, 3D scatter plots).  Simply click the color button on any of the other axes, click apply, and the color bar moves to that axis, and the colors of the lines are defined according to the variable associated with that axis. 

NOTE: If two or more axes are selected as the color axis, the color bar, by default, assigns the color axis to the one furthest left.  As illustrated in the first figure at left, if you are moving the color bar to the right, you must assign the existing color axis to another display position (like z-axis). 

Go to the sample plot. 

Go to the users guide home page. 

Go to the web version of the paper.