One of the best submissions here. This deserve more attention. Its super smooth, idea is great and execution is flawless. Good job!
Improvement suggestion: from UX perspective it would be great if there is some label which says "Press Space to change color" or something like that. First time i played it, i didnt read description and i was wondering whats going on here. But if you put one time text (which can fadeout after first color change so its not too much invasive), it could clear a lot of confusion for first time plays and since this mechanic is so simple (love it! love simple ideas), player will imidiatelly understand how it plays