I don't know anything about Frank Lloyd Wright quilts, but Frank Lloyd Wright was known for bringing the outside indoors. He incorporated a lot of windows in his structures. I would think greens and browns and blues would be the color choices to go with. Or maybe the oranges and reds of Autumn. Whatever colors are found in nature during different seasons would work. But the first color that comes to mind is green. Some of his houses take advantage of the water around them too, so blue could also work.