Wiring of SMD RGB LED
You appear to be using P-channel MOSFETs to do low-side switching which is an odd choice due to the more complex gate driving arrangement that would be required. On top of this you won't be able to turn off the load.

You'd be better off with N-channel MOSFETs for switching loads to ground, the gate driving is very simple if you use logic level MOSFETs and not much more complicated if you don't. The body diode will also not allow the LEDs to light all the time as it'll be reverse biased when the FET is turned off.

EDIT: I would also move the resistors so they are between the LEDs and the MOSFETs and the source of the MOSFETs is directly connected to ground.