docs: def get_system_bck_color():
          """
          Gets a system color for drawing the fold scope background.
          """
          def merged_colors(colorA, colorB, factor):
              maxFactor = 100
              colorA = QtGui.QColor(colorA)
              colorB = QtGui.QColor(colorB)
              tmp = colorA
              tmp.setRed((tmp.red() * factor) / maxFactor +
                         (colorB.red() * (maxFactor - factor)) / maxFactor)
              tmp.setGreen((tmp.green() * factor) / maxFactor +
                           (colorB.green() * (maxFactor - factor)) / maxFactor)
              tmp.setBlue((tmp.blue() * factor) / maxFactor +
                          (colorB.blue() * (maxFactor - factor)) / maxFactor)
              return tmp
  
          pal = QtWidgets.QApplication.instance().palette()
          b = pal.window().color()
          h = pal.highlight().color()
          return merged_colors(b, h, 50)