Very nice concept. Would have liked to see a board size option in the generator so I can start with some easier levels. Switching the blocks a round to count them is a nice mechanic. On this board size it's hard for me to decide whether I find that activity tiresome or meditating. :D
Giving the player feedback on how many colors are already correct when pressing the check button would feel quite encouraging in my opinion. That way you could feel more like you're making progress while rearranging the colors. To prevent people from abusing that and just solving it by trial and error you could limit the check button to 10 checks or something like that.
Overall very interesting and unique. Definitely glad I gave it a shot. Nice, nice. :)