In the Palace intro scene I posted earlier, there are 52 unique onscreen colors.
I think both versions use the same techniques and possibly the same source assets; it's just that the Amiga version was possibly better about creating combined palettes and not wasting colors, since it had to (only 32 onscreen at once). The MCGA version is clearly a little lazier; you can see in the palettes that each element in the dungeon (background tiles, sprite #1, sprite #2) have their own 16-color entry/range in the total 256-element palette.
I don't fault them for that -- If all my source assets were 16 colors or less, and I had 256 to work with, that's exactly how I'd do it as well. There's no full-screen animation in POP, only localized small updates (it did originate on the Apple II in double-high-res so minimizing screen writes was mandatory) so using full-blown MCGA is not a problem -- there was no need for the speed of a 16-color mode.
Offering a bounty for:
- Music Construction Set, IBM Music Feature edition (has red sticker on front stating IBM Music Feature)