Lovely concept! Although It took me a while to really understand it. I didn't get immediately that the colors were strictly associated with numbers. And being colorblind, I was confused that a grey dice was counting as the same "color" as an orange one, or that two shades of blue were actually the same, or two purples were different… (also I just can't see the "yellow on the left" mentioned in the tutorial) Once I understood that I just had to focus on the numbers, it became way easier! I think the tutorial could be more direct: talking about "making the prettiest art", "colors that goes badly together", while setting a tone, also creates confusion. In the end the rules can be explained in a more straightforward way: two identical numbers must not share the same zone. Plus, I find a bit odd that a game about creating art is so judgmental about what's beautiful or not right at the beginning. :P
However once I understood the rules, I had a lot of fun playing the game! It's a very interesting puzzle, that demands to schedule and adapt constantly. And it's very relaxing on top of that. Maybe the randomness of the pieces could be better balanced though: I had several games with almost nothing but dices above 6 (very hard to place without losing points), and even one where I never saw the color of a 7 and felt like I had the same numbers pop up for the 6 last rounds. :P I don't know if the selection is completely random, but maybe it can use a pool, or make some numbers less likely to appear.
Anyway, it was still a very pleasant game. With really great visuals I must say! While the tutorial is confusing, the UI of the game is really sweet! Being able to see the dices zones by hovering them is a great decisions, and helps a lot understanding what's on the screen. Despite my difficulties I really liked playing several games just to see how I could optimize my score, and enjoy the end result. Congratulation for this neat work!