load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"

begin
  wks = gsn_open_wks("ps","color3")     ; Open color3.ps PostScript file
  gsn_define_colormap(wks,"rainbow")    ; Change color map.
  gsn_draw_colormap(wks)                ; Draw color map.
end