When no switch is plugged in, the lights cycle through the 8 bright colours, fading gently between them.
Plug a single switch into the 'step colour' socket and each time you activate the switch the colour will change.
Plug another into the 'on-off' socket and the bubbles will stop and start with each touch of the switch.
Plug a Nine Switch Keyboard into the 'step colour' socket and you can choose any colour directly and even touch two colours to colour mix. You can also switch the bubbles separately.