code: def color_conversion_function(start_type, target_type):
      
      def decorator(f):
          f.start_type = start_type
          f.target_type = target_type
          _conversion_manager.add_type_conversion(start_type, target_type, f)
          return f
  
      return decorator
docs: Decorator to indicate a function that performs a conversion from one color
      space to another.
  
      This decorator will return the original function unmodified, however it will
      be registered in the _conversion_manager so it can be used to perform color
      space transformations between color spaces that do not have direct
      conversion functions (e.g., Luv to CMYK).
  
      Note: For a conversion to/from RGB supply the BaseRGBColor class.
  
      :param start_type: Starting color space type
      :param target_type: Target color space type