Like mokesmoe said above, I think the jam rules should be reworded to allow any kind of output as long as it is on or off, 1 bit, no inbetweens.
"make a game in 1-bit colour, on a 1px × 1px display with no audio; the minimum (non-zero) feedback that a game could possibly have."
perhaps changed to
"make a game in 1-bit colour, on a 1px × 1px display; the minimum (non-zero) feedback that a game could possibly have. For accessibility purposes, you can replace using visual feedback with using audio feedback in its place, or any other kind of 1-bit, on/off feedback. You can even use multiple feedback methods in the game, as long as they convey the same, exact, synchronized information. (issue a beep sound at the same time you turn the screen color to 'on', then stop the beep sound at the exact same time you stop showing the 'on' color, switch to the 'off' color instead). Alternatively using different methods of feedback, like sometimes flashing the screen and sometimes beeping is not allowed."