Add an independent color scale in a graph. It is useful when the graph has plots mapping to a palette or color list.
Syntax: spectrum -i
Add an independent color scale. Refer to this page for details.
The following script creates a color-filled contour and then add a color scale independent from the contour.
matrix -v i+j;
plotm plot:=226 ogl:=<new template:=CONTOUR>;