I feel it best to use the color change of 10 when you are on the derp face, 5 or 6 when on the flowers, 3 on the food and about 25 on the color wheel.
This literally took me 20 sec. to make I think that it is a nice concept to change the color of the background, especially when the background already has a lot of colors in it. It looks really cool. Feel free to remix and add more backgrounds!