class_docstr: Base class for color transformations. All color transformations need to
  inherit from this base class. ``ColorTransform`` unifies the class
  attributes and class functions of color transformations (Color, Brightness,
  Contrast, Sharpness, Solarize, SolarizeAdd, Equalize, AutoContrast, Invert,
  and Posterize), and only distort color channels, without impacting the
  locations of the instances.
  
  Required Keys:
  
  - img
  
  Modified Keys:
  
  - img
  
  Args:
      prob (float): The probability for performing the geometric
          transformation and should be in range [0, 1]. Defaults to 1.0.
      level (int, optional): The level should be in range [0, _MAX_LEVEL].
          If level is None, it will generate from [0, _MAX_LEVEL] randomly.
          Defaults to None.
      min_mag (float): The minimum magnitude for color transformation.
          Defaults to 0.1.
      max_mag (float): The maximum magnitude for color transformation.
          Defaults to 1.9.
code: def __repr__(self) -> str:
      repr_str = self.__class__.__name__
      repr_str += f"(prob={self.prob}, "
      repr_str += f"level={self.level}, "
      repr_str += f"min_mag={self.min_mag}, "
      repr_str += f"max_mag={self.max_mag})"
      return repr_str
  
imports: import math
  from typing import Optional
  import mmcv
  import numpy
  from mmcv.transforms import BaseTransform
  from mmcv.transforms.utils import cache_randomness
  from mmdet.registry import TRANSFORMS
  from .augment_wrappers import _MAX_LEVEL, level_to_mag
label_desc: Use image node_id 6 for calling the ColorTransform obj's underlying member method code with example usage: obj.__repr__() and returns: repr_str