functions in idl-colors.i -

             loadct, which;  
             color_names= loadct();  
 
     In the first form, load IDL color table identified by WHICH (either  
     a number or a name).  When called as a function, e.g., second form,  
     returns an array of names of color tables.  
     Keyword FILE can be used to indicate an alternate file name (default  
     is Y_SITE + "data/colors1.tbl").