Okay this game is extraordinary. Unfortunately I had to stop after 30 minutes because its pretty late and I need to go to bed. This game would benefit from a save system!
This game gives me vibes of The Witness. Your hub area is so intriguing, and I really want to complete it. I love how unlocking a puzzle will unlock a new hall to go solve puzzles in. The puzzles are really challenging, but doable. I had to read your description to get what they meant, but I appreciated the tutorialization you tried to get the player through at the beginning. I think the visuals look really nice, and the audio was extremely satisfying.
My only feedback would be that it would be really nice to have a way to reset squares back to the non-color position, and/or reset the entire board at once.
I loved this one.