retrieve colormap

   # retrieve workstation's current colormap…

   tmpCmap = gsn_retrieve_colormap(wks)

  

   # load default.rgb into workstation and then retrieve it…

   gsn_define_colormap(wks, "default")

   defaultCmap = gsn_retrieve_colormap(wks)

  # restore original workstation colormap…

  gsn_define_colormap(wks, tmpCmap)

Answering from Rick in ucar