We are required to use 1-bit graphics, but can we have a button that switches the palette? Obviously changing the palette due to stuff happening in-game would be a very direct breaking of the two colour rule, but I feel like if it's not attached to anything in-game it shouldn't break the spirit of the rule and it will help with accessibility.
(Another point is that it should be usable at all times during the game, so that it can't be used to check what state you are in.)
My second question is if I can use a save file. A save file that is human readable would technically be another source of output, which could be used to verify information about the game.