Driving three high power RGB LEDs with PWM, from a 9v battery
If you power off 9V then consider using some of the 3W LEDs in series: -



Typically red leds need about 2.5V across them so wiring three in series will need at least 7.5V then there should be some current limiting circuit that might take 0.5V.

Typically for blue or green leds they need 3.4V across them so maybe only series together two LEDs.

You might just about get enough brightness with the NCP5623 chip this way but if not you'll need a current limit circuit and mosfets. The NTD80N02 looks OK but you need to limit current into the LEDs.