click the stage to change the backdrop and change the color of the medallion(s) when working on another project, it seemed like the "when backdrop switches to..." hatblock didn't affect clones, but it seems to be working here ¯\_(ツ)_/¯ UPDATE : press space to change the backdrop it turns out the "next costume" block, when used on the stage, changes the backdrop without triggering the "when backdrop switches to..." hatblock ! that's what was going on in my other project :)