cl[/qualifiers]
The maximum number of levels that can be used depends on the display device used. The default number of levels is set equal to the maximum allowed by the plot device currently defined. If the graphic device used does not allow this, the number of levels is automatically reset to the maximum value allowed.
defines nn as the number of colour levels to be used for the image display.
Example:
cl/n=20 ! Sets the number of colour levels to 20.