anchor.diff:              read(tag,*) lim1,lim2,dz
           elseif (tag(1:2).eq.'-v') then
               vrb = 1
  +        elseif (tag(1:2).eq.'-D') then
  +            saturate = 1
           elseif (tag(1:2).eq.'-d') then
               call usage('long')
           else
  
positive.code:     vrb = 0
      dz = -1.0
      gmt = 'none'
      narg = iargc()
      if (narg.eq.0) call usage('')
      i = 1
  
negative.code:     endif
      write(0,*) 'Usage: colortool [-cmap OPTION] [-hue H1,H2] [-lightness L1,L2] [-chroma C1,C2] [-n[colors] N]'
      write(0,*) '                 [-convert ITYP=X,Y,Z OTYP] [-v verbose] [-gmt CPTFILE] [-limits MIN,MAX] [-dz DZ]'
      write(0,*) '                 [-Tzmin/zmax/dz] [-D] [-d]'
      write(0,*)
      write(0,*) '-cmap OPTION              Option to generate a colormap'
      if (str.eq.'long') then
  