I really like the idea and execution behind this game, well done!
The only issue I have is the controls. 3 sliders takes too long and is too slippery for my liking.
Most art programs use a 2d color picking area with only 1 slider and there are even options to avoid sliders all together like in the google example below:
Now I'm not sure if 0 sliders is optimal, but 3 is too much for me personally.
Anyway the game idea is great and the daily play mode is a nice incentive to come back to the game