code: def plot_eeg_erp_topo(all_epochs, colors=None):
      
      all_evokeds = eeg_to_all_evokeds(all_epochs)
  
      data = {}
      for participant, epochs in all_evokeds.items():
          for cond, epoch in epochs.items():
              data[cond] = []
      for participant, epochs in all_evokeds.items():
          for cond, epoch in epochs.items():
              data[cond].append(epoch)
  
      if colors is not None:
          color_list = []
      else:
          color_list = None
  
      evokeds = []
      for condition, evoked in data.items():
          grand_average = mne.grand_average(evoked)
          grand_average.comment = condition
          evokeds += [grand_average]
          if colors is not None:
              color_list.append(colors[condition])
  
      plot = mne.viz.plot_evoked_topo(evokeds, background_color="w", color=color_list)
      return(plot)
docs: Plot butterfly plot.
  
      DOCS INCOMPLETE :(