Prism99

I like 4 the best. If using just 3 fabrics with the background, I would choose 1, 4, and either 6 or 7 but not both (they are very similar).

Edit: Looking at the blocks together from a distance, I like the depth added by the darker fabric so I would add that in too. You could also add one of the light fabrics, but both would be too much. A few very light and very dark blocks would add interest; too many will compete with the medium-tone blocks.