code: def monochrome(clr):
      
      def _wrap(x, min, threshold, plus):
          if x - min < threshold:
              return x + plus
          else:
              return x - min
  
      colors = colorlist(clr)
  
      c = clr.copy()
      c.brightness = _wrap(clr.brightness, 0.5, 0.2, 0.3)
      c.saturation = _wrap(clr.saturation, 0.3, 0.1, 0.3)
      colors.append(c)
  
      c = clr.copy()
      c.brightness = _wrap(clr.brightness, 0.2, 0.2, 0.6)
      colors.append(c)
  
      c = clr.copy()
      c.brightness = max(0.2, clr.brightness + (1 - clr.brightness) * 0.2)
      c.saturation = _wrap(clr.saturation, 0.3, 0.1, 0.3)
      colors.append(c)
  
      c = clr.copy()
      c.brightness = _wrap(clr.brightness, 0.5, 0.2, 0.3)
      colors.append(c)
  
      return colors
docs: Returns colors in the same hue with varying brightness/saturation.