code: def palettize(self, colormap):
          
  
          if self.mode not in ("L", "LA"):
              raise ValueError("Image should be grayscale to colorize")
  
          l_data = self.data.sel(bands=['L'])
  
          def _palettize(data):
              # returns data and palette, only need data
              return colormap.palettize(data)[0]
  
          new_data = l_data.data.map_blocks(_palettize, dtype=l_data.dtype)
          self.palette = tuple(colormap.colors)
  
          if self.mode == "L":
              mode = "P"
          else:
              mode = "PA"
              new_data = da.concatenate([new_data, self.data.sel(bands=['A'])], axis=0)
  
          self.data.data = new_data
          self.data.coords['bands'] = list(mode)
docs: Palettize the current image using `colormap`.
  
          .. note::
  
              Works only on "L" or "LA" images.