code: def palettize(self, colormap):
          
  
          if self.mode not in ("L", "LA"):
              raise ValueError("Image should be grayscale to colorize")
          self.channels[0], self.palette = colormap.palettize(self.channels[0])
          if self.mode == "L":
              self.mode = "P"
          else:
              self.mode = "PA"
docs: Palettize the current image using
          *colormap*. Works only on"L" or "LA" images.