dimming filament wire colours to create RGB

I am about to buy some red, blue and green filament wire separately and plan to twist them together and control each colour's brightness to make every possible colour together. I am using a raspberry pi 0 W. I would be grateful if anyone could point out any other hardware or anything else I need to buy to make this possible? Do I really need a mosfet or pwm controll? I already have an adafruit bonnet with power supply for two 64x32 matrices.

Also gonna cut up some rgb tape and put it behind a diffuser to make sum glowing panels