the matrix works ;D
the red leds suck way too much current. relative brightness needs adjustment to get close to white light. overall brightness not yet acceptable. 4bit pwm is feasible with hardware SPI (fosc/4). no flicker. if this will run properly with an ISR remains to be seen. maybe I can get 6 or 8bit pwm to work. will investigate SPI with fosc/2. enable/disable pins should not be left floating...
the rgb leds may be miniscule, but they're damn bright.