Last time I did a GBJam was the very first edition I believe, so I don't remember at all if anything like this is allowed. It says you must use 4 colors only in your game, but if you swapped to different palettes in the middle of the game, would that be allowed? I assume not but still thought I'd ask

i dont think your alowed to swap for say for example a day night thing or any other reason, however i think people could apriciate having a couple of pallets they can change to manualy for people who are colorblind or just similar how the gbc/gba did it at startup.