There are 2 banks of 256 palettes of 16 colors available, made of 16bit RGB definitions. Palettes are located at $400000 in the 68k's memory map.
The bank used for video output is set by registers REG_PALBANK1 ($3A000E) and REG_PALBANK0 ($3A001E).
Only one bank can be used at a time. They can be switched by using register ???
Color definition word: D R0 G0 B0 R4 R3 R2 R1 G4 G3 G2 G1 B4 B3 B2 B1
Max colors on screen without RLI tricks: 256*16=4096 out of 2^16=65536.
Palettes are stored in Palette RAM.