First of all, congratulations on submitting such a polished prototype. This game idea has crazy potential. Without a doubt, it inspires me to think of more "paint" to create more puzzles and interactions. Any game idea that encourages that type of thinking is a great start!
I love the aesthetic. I love the sounds. I love how the world moves cleanly from Greyscale to Chroma. I love the functional puzzle design. The dialogue / inner monologue is excellent and appropriate. Great technical details like a seamless save/respawn system.
My only feedback is that it's hard to determine that the project is "on theme". I get the idea of renewing the colors, but really it's more about playing the game which happens to coincidentally change colors!
Excellent project!