Connecting RGB led to the output of the op amp with resistor
That depends on how bright you want them.

An LM741 is only good for 25mA MAX before it goes into current limit. So if you are planning on driving those LEDs with more than about 8mA each, then no the poor old 741 can't drive them that hard.

Driving the 741 at +-12V will also put too high a reverse voltage on the LEDs at around -10V output. You would need to add a diode to protect the LEDs.

Ultimately you would be better adding an NPN Transistor or a suitable MOSFET.







simulate this circuit &ndash; Schematic created using CircuitLab

The diode D2 in the above protects the base-emitter junction of the NPN from breaking down when the op-amp output is negative.

BTW, if you just want a white LED you would be better with a single white LED, and the 741 is very old technology. Although Op-Amps can be used as comparators like that, they are not great at the role, a suitable actual comparator, with sufficient drive, would be a better choice all round.