It's beautiful, and random can be good. But if it were mine, I'd group those lighter blocks together more, perhaps off to one corner which would give them much more impact. Do you have any way of putting up a quick 'design wall'? A piece of batting hung over a curtain pole or the flannel back of a vinyl table cloth suspended from skirt hangers? You'll find it much easier to get an impression of your layout if you can see it vertically. Great job though. The fabric turned out great.