code: def _render(self):
          
          if self.set_device_brightness:
              level = 1.0
          else:
              level = self._brightness / 255.0
          gam, (r, g, b) = self.gamma.get, self.c_order
          for i in range(min(self.numLEDs, len(self._buf) / 3)):
              c = [int(level * x) for x in self._colors[i + self._pos]]
              self._buf[i * 3:(i + 1) * 3] = gam(c[r]), gam(c[g]), gam(c[b])
docs: Typically called from :py:func:`_compute_packet` this applies
          brightness and gamma correction to the pixels controlled by this
          driver.