Your game gave me good memories - my very first jam game had a similar theme (https://bom222243.itch.io/colored) and it was so exciting back then to do a jam :-D
You idea is quite interesting, collecting the color is giving the world this color back, and is also activating enemies in that color. I struggled to understand how to defend against the enemies, as they follow you very closely, and I couldn't really see a tactic against them. In your tutorial video one can see a dash or something, but at least some control explenations would be helpful for such moves (same for the jump, only by luck I found it, and almost gave up right in the first level). I also haven't really understood the weapon, I happily picked it up, only to instantly get attacked by all monsters. Maybe I have to outrun these too, or is picking up the weapon just a bad idea? And if so, why?
A QOL feature would be to speed up the text, the german translation was pretty good, though.