If you are using 200 ohms in series with one LED you must use 200/3 ohms in series with three LEDs if you are connecting the LEDs in parallel and expect to keep the light intensity the same. You must use the equivalent of three 200 ohm resistors in parallel since you are using three LEDs in parallel. If I understand you correctly you are attempting to use a higher value resistor when you connect the LEDs in parallel. This is the opposite of what is required.