class_docstr: Represent colors by specifying their Red, Green, and Blue channels.
  
  Alpha values may also optionally be provided. Otherwise, alpha values
  default to 1.
class_docstr_tok: ["Represent","colors","by","specifying","their","Red",",","Green",",","and","Blue","channels",".","Alpha","values","may","also","optionally","be","provided",".","Otherwise",",","alpha","values","default","to","1","."]
docstr: Initialize ``RGB`` instance from a 3- or 4-tuple. 
docstr_tok: ["Initialize","``","RGB","``","instance","from","a","3-","or","4-tuple","."]
code: def from_tuple(cls, value: RGBTuple) -> RGB:
      """Initialize ``RGB`` instance from a 3- or 4-tuple."""
      if len(value) == 3:
          r, g, b = value
          return RGB(r, g, b)
      else:
          r, g, b, a = value
          return RGB(r, g, b, a)
  
imports: from __future__ import annotations
  import logging
  import colorsys
  from abc import ABCMeta, abstractmethod
  from math import sqrt
  from re import match
  from typing import TYPE_CHECKING, Union
  from ..core.serialization import AnyRep, Serializable, Serializer
  from ..util.deprecation import deprecated
label_desc: Use image node_id 5 for calling the RGB obj's underlying member method code with example usage: obj.from_tuple(cls, value) and returns: RGB, RGB