Great art style and the music fits the atmosphere really well! The whole color-swap mechanic is a really creative take on the theme.
I think the color swaps of projectiles should be synced maybe? Since right now the warning sound effect doesn't help much + it's really difficult to get into a rhythm. Keeping track of your character + the projectiles and their current/future color is enough of a challenge; juggling multiple entities and timings I think is too much for the brain.
Anyways, good job!