I was thinking more of the sort of 18-bit C2P routines that you can find on aminet, but even HAM6 would be neat.
Oh I spoke in jest; Quake has an 8-bit pallet and would hardly benefit from 12-bit

Tell me more of these 18-bit routines, though. I'm a coding newborn and didn't touch anything on the Amiga post AmigaBasic though so be gentle.