A cool concept once you grasp it !
I like how this is sort of a new twist on the Ikaruga style where you have to color match but here it’s to shoot rather than to avoid bullets.
The music is also quite good in this and i like Ultramato’s design, the character somehow gave me some Katamari Damaci vibes XD
if i had to nitpick i’d say that while the color switch mechanic is really cool and what makes the game, the controls to change it kinda hinder the experience a bit. Cause you’ve gotta quickly tap the spacebar to find the right color and sometimes can overshoot it and have to cycle everything again :/
one way to improve this could be to have the color switch on some sort of wheel selection (mechanically i was thinking kinda like weapon wheels in some FPS) so the player could quickswitch directly to the color they need instead of having to cycle through it all every time. Then again just a suggestion ^^
Other than that its pretty fun to play, well done :)