$this->rgb = new RGB(
          bcmul(bcadd($red, $m, self::$bcscale), RGB::MAX_RGB, self::$bcscale),
          bcmul(bcadd($green, $m, self::$bcscale), RGB::MAX_RGB, self::$bcscale),
          bcmul(bcadd($blue, $m, self::$bcscale), RGB::MAX_RGB, self::$bcscale),
          $this