@Acorn Although Iminei says the background and sashing strips will be the same, you don't have to do it that way if you don't want to.
You could use that turquoise as the block background and have a light sashing, or....
If you arrange those fabrics in one lot, dark to light do they look better or worse? As a general rule, your darkest should be really quite dark, and the lightest fairly light. mix them together and see how they look then.
Personally, atm, I would be inclined to remove the pale spot from the green pile; all the rest are quite random patterns and the spot on its own might stick out like a sore thumb. Possibly take out the top one on the blue pile and have the second down green as the lightest. The turq background reads plain from a distance so look at how the others stand up to it - they need to show up rather than blend. Try adding (if you have any) something in the gold to red-orange range and see if that helps; blue and green are adjacent on the colour wheel, red is opposite green, orange is opposite blue. You probably wouldn't need much, just a dash to sharpen up the rest. A quiet evening with squared paper and coloured pencils, trying out ideas can be useful. Most blocks depend on placement of value - light or dark - to give the design. You could even use all sorts of things and a consistent background would tie them all together.
We all have opinions and preferences, but it's yours that matter - in the end it's your quilt and you do what you like. It will be fine.