Tip: Layer 3 backgrounds and tides disappear when you hit a message box, so plan your level around that. For example, you can add a sublevel without layer 3 at the start/midpoint, and include your message there.
This block pack is inspired by SMWCP's level named "Switch of Many Hues". When Mario presses a colored switch, the corresponding colored blocks will become solid while all other colors will be deactivated (so only 1 color switch is always activated, like radio buttons). Very useful for designing puzzle levels.
I made this using the manual trigger of LM.
Read the readme to setup the blocks correctly.