anchor.diff:      chroma1 = 40.0
       chroma2 = 40.0
       ncolors = 10
  +    convert1 = ''
  +    convert2 = ''
       vrb = 0
       narg = iargc()
       if (narg.eq.0) call usage('')
  
positive.code:     implicit none
      real :: l,c,h,a,b,a1,a2,b1,b2
      real :: red,grn,blu
      character(len=200) :: rgbstring
      real :: cmax
      integer :: i,n
      integer :: clip(3)
  
      ! User-defined variables
      real :: hue1,hue2,light1,light2,chroma1,chroma2
      character(len=200) :: option
      integer :: ncolors,vrb
  
      ! Parse command line
      call gcmdln(option,hue1,hue2,light1,light2,chroma1,chroma2,ncolors,vrb)
      if (vrb.gt.0) then
          write(0,*) 'Color mapping option: ',trim(option)
          write(0,*) 'Hue range:            ',hue1,hue2
          write(0,*) 'Lightness range:      ',light1,light2
          write(0,*) 'Chroma range:         ',chroma1,chroma2
          write(0,*) 'Number of colors:     ',ncolors
      endif
  
      n = ncolors
      if (option.eq.'spiral') then
          do i = 1,n
  
negative.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
      elseif (option.eq.'linear') then
          call lch2lab(chroma1,hue1,a1,b1)
  