Seems like it's trying to generate a bunch of aesthetically-pleasing 4-color palettes, and present them in a helpful way.

I suspect that the building shape is engineered to create a border between each pair of colors. (The standard alternative would be, say, 4 vertical bars, which only shows you how 3 of the color pairs look against each other.)

The noise might be working under the assumption that you're going to apply noise to the colors when you use them, too.