docs: def _assert_is_color(value):
          """
          Assert that the given value is a valid brightness.
  
          :param value: The value to check.
          """
          if not isinstance(value, tuple) or len(value) != 3:
              raise ValueError("Color must be a RGB tuple.")
  
          if not all(0 <= x <= 255 for x in value):
              raise ValueError("RGB values of color must be between 0 and 255.")