Just in case you end up needing more current since multiplexed leds
need a lot when they're on, the ACT (I THINK!!  One of the not too
common series..)  the 574 can source 48 and sink 64 milliamps..



> 2) Using 74hc374 (Octal Latch) for each LED colour.
>     This would allow 16 LEDs to light at once (giving a brighter
> display) & is easy to get colour mixing. This uses PIC port
> RB as an 8 bit bus, which is connected to the inputs of each
> Octal Latch & directly to the collum drives (For up to 8
> collums). Two other PIC O/Ps are used to latch the data into
> each Octal Latch. The -OE (Output Enable) lines of the
> latches could be tied LOW, always enabled.