Thank you for your detailed reply! I was indeed using colorgif already and had worked out how to hide it and make it appear when the button is pressed as you mention, but that was as far as I had gotten with it. Thank you so much for updating the gif contraption to make this work the way I wanted. I used your code and it all works beautifully now.
I have a small follow up question if that's ok (not related to gifs). I was wondering if there's a way to do the same thing with sounds as you did with the gif. So rather than waiting until the sleep ends before the sound plays, it could play as soon as the button is pressed. I have the code to start the sound on the same button as the code that begins the gif, but of course the sound only begins playing after the transition to the next card.
Sorry for all the questions, but your last reply was very helpful so I'd be remiss not to ask.