anchor.diff:      chroma1 = 40.0
       chroma2 = 40.0
       ncolors = 10
  +    convert1 = ''
  +    convert2 = ''
       vrb = 0
       narg = iargc()
       if (narg.eq.0) call usage('')
  
positive.code:             call lab2rgb(l,a,b,red,grn,blu)
              call checkrgb(red,grn,blu,clip)
              call formatrgb(red,grn,blu,rgbstring)
              print *,trim(rgbstring)
          enddo
      else
          call usage('!! Error: no option named "'//trim(option)//'"')
  
negative.code:     y = yin/refy
      z = zin/refz
      if (x.gt.0.008856) then
          x = x**(1.0/3.0)
      else
          x = 7.787*x + 16.0/116.0
      endif
      if (y.gt.0.008856) then
          y = y**(1.0/3.0)
      else
          y = 7.787*y + 16.0/116.0
      endif
      if (z.gt.0.008856) then
          z = z**(1.0/3.0)
      else
          z = 7.787*z + 16.0/116.0
      endif
  