code: def to_rgba(
      colors: Sequence[ColorType], alpha: float
  ) -> Sequence[ColorType] | ColorType:
      ...
  
imports: from __future__ import annotations
  import inspect
  import itertools
  import warnings
  from collections import defaultdict
  from collections.abc import Iterable, Sequence
  from contextlib import suppress
  from typing import TYPE_CHECKING, cast, overload
  from warnings import warn
  import numpy
  import pandas
  from pandas.core.groupby import DataFrameGroupBy
  from ..exceptions import PlotnineError, PlotnineWarning
  from ..mapping import aes
label_desc: Use image node_id 16 for calling a global function with example usage: to_rgba(colors, alpha) without return types