I am what I call a lazy quilter. I usually just have 3 materials. I use a rectangle in the center (like your green), then strips on the side & top of the rect. with the next color (maybe the red), then strips on the side & top again with my 3rd color. Then I repeat strips beginning with the center color. I will then use a different binding color to compliment or the center color. Hope this is helpful. I figure out my center and strip sizes by determing how big I want my quilt & then work backwards.