Hi Alan,
Thankyou for your comment about my orrery, it's nice to know someone liked it !.
Regarding Charlieplexing 60 RGB CC LEDs, it can be done with 16 pins, so a 28X2 could do it easily.
The circuit is no more complex than a 'normal' multiplexed arrangement, it's just that there is no easy pattern, so it needs more care when wiring. That's why I wrote a VB prog to layout the LED positions, another to 'wire' the LEDs, and another to calculate the pin switching. It was a real 'labour of love', and I wouldn't do it again !.
Even so, for what the OP wants, I would say Charlieplexing is the best way. Much less wiring, no driver chips, and some clever code.
Happy New Year !