code: def color_noise(self, segment_size, color):
      # https://en.wikipedia.org/wiki/Colors_of_noise
      uneven = segment_size % 2
      fft_size = segment_size // 2 + 1 + uneven
      noise_fft = np.random.randn(fft_size)
      color_noise = np.linspace(1, fft_size, fft_size)
  
      if color == "random":
          _color = np.random.choice(self.COLOR_NOISES)
      else:
          _color = color
  
      if _color == "white":
          pass  # no color noise
      else:
          if _color == "pink":
              color_noise = color_noise ** (-1)  # 1/f
          elif _color in ["red", "brown", "brownian"]:
              color_noise = color_noise ** (-2)  # 1/f^2
          elif _color in ["blue", "azure"]:
              pass  # f
          elif _color in ["violet", "purple"]:
              color_noise = color_noise**2  # f^2
  
          noise_fft = noise_fft * color_noise
  
      if uneven:
          noise_fft = noise_fft[:-1]
  
      noise = np.fft.irfft(noise_fft)
      return noise, color_noise
  
file_path: nlpaug/nlpaug/model/audio/noise.py
imports: import random
  import numpy
  import math
  from nlpaug.model.audio import Audio
label_desc: Use image node_id 3 for calling the Noise obj's underlying member method code with example usage: obj.color_noise(segment_size, color) and returns: noise,  color_noise