If you want to stop rainbow click the rainbow sprite and type the answer,"no rainbow."If you type the answer no rainbow and want the rainbow again just hit that green flag.(glitch)If you want no music then click the speaker and type the answer,"no music."if you want to change the volume click the speaker and it will do you want to change the volume and type yes if you want to change it.also if you want no music for the number type 0.
https://scratch.mit.edu/projects/420519342 by KVlpa2020 for code and https://scratch.mit.edu/projects/1260238668 by MrScratcherAP for rainbow idea