One of the easiest ways to improve basically all of the rhythm motion options is a way to let the user change the default/"background" color.
Most of the time it's black (off), and for the firmament it's a bright blue. But if I could change the default color on any of these—or if that color we're chosen from the selected pallet—I'd find all of the rhythm functions more versatile and useful.
As it is if the music isn't necessarily loud enough to trigger a really active display, the panels spend a lot of time on the background color, so it would be nice to be able to modify it to fit with the color scheme.
(The firmament motion is the worst—it seems to ignore the palate entirely, but in the app it pretends that you can actually change it.)