Rainbow Bubble is a Processing sketch based on a bubble tube with a rainbow effect.
Open the RainbowBubble.pde sketch in Processing and click Export Application from the File menu, fill in the desired settings and click the Export button. The pre-built versions are available for the following platforms and architectures:
Apologies to anyone using macOS but Processing doesn't allow me to export sketches for it as I am using Arch GNU+Linux.
Download and install a Java Runtime Environment and run the RainbowBubble script from the directory matching the OS and processor (probably application.*something*64) or alternatively, open RainbowBubble.pde in the Processing IDE and click the Run button on the top-left.
Once the program is running, it can be influenced with the following keys
Rainbow Bubble is licensed under the Apache License 2.0.