anchor.diff:          write(0,*) str
           write(0,*)
       endif
  -    write(0,*) 'Usage: colortool -cmap OPTION [-hue H1,H2] [-lightness L1,L2] [-chroma C1,C2] [-ncolors N]'
  -    write(0,*) '                 [-convert ITYP=X,Y,Z OTYP] [-v verbose] [-d]'
  +    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] [-dc D] [-d]'
       write(0,*)
       write(0,*) '-cmap OPTION              Generate a perceptually linear colormap'
       if (str.eq.'long') then
  
positive.code:             call lab2rgb(l,a,b,red,grn,blu)
              call checkrgb(red,grn,blu,clip)
              call formatrgb(red,grn,blu,rgbstring)
              write(*,*) trim(rgbstring)
          enddo
      else
          call usage('!! Error: no option named "'//trim(option)//'"')
      endif
  end
  
  !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!
  
negative.code: ! User interface subroutines
  !~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!
  
  subroutine gcmdln(option,hue1,hue2,light1,light2,chroma1,chroma2,ncolors,vrb,convert1,convert2,&
                    gmt,lim1,lim2)
      implicit none
      integer :: i,j,narg
      character(len=200) :: tag
      character(len=*) :: option,convert1,convert2,gmt
      character(len=1) :: ch1,ch2
      real :: hue1,hue2,light1,light2,chroma1,chroma2,lim1,lim2
      integer :: ncolors,vrb
      real :: dc
      option = ''
      hue1 = 0.0
      hue2 = 360.0
  