code: def get_color_table_size(num_colors):
      
      nbits = max(math.ceil(math.log(num_colors, 2)), 2)
      return '{:03b}'.format(int(nbits - 1))
docs: Total values in the color table is 2**(1 + int(result, base=2)).
  
      The result is a three-bit value (represented as a string with
      ones or zeros) that will become part of a packed byte encoding
      various details about the color table, used in the Logical
      Screen Descriptor block.