from the top picture i would remove the middle 3- they are too (medium)...blend it all together rather than create contrast.
sometimes it is hard to not have all mediums---
one way to do it is to take a picture of the fabrics layed out like you have them-then print the picture in grayscale-
with the color gone you see the distinct values- light, medium and dark= that way you can see what is blending and what is contrasting
i like the fabrics- will make a wonderful quilt