What I love about this is how the over-lay of the shapes almost in itself creates a pattern. The new shapes and colours that are created really excites me.
Next, I decided to continue this idea by comparing this with less of an over-lay of the shapes.
While I still like this layout, and think it could work as a background (perhaps with negative or white shapes/pattern on top), when I first looked at it I found it to be too much. Strangely the many many shapes formed in the first layout makes it a bit of a blur and a haze, making it easier on the eye. Whereas this layout gives more for the eye to follow, possibly making it too much information? Am I right? Or is it actually the other way around? I need some distance and outside perspective to see this for me.
And so from there I decided to see what this layout would look like with more negative space (in colour). This would leave room for a pattern as a background as well as the one in the foreground.
Here I went with a colour theme to keep the pattern slightly simpler. However I do feel that this could work well with each of the 3 squares in each set being a different colour. That was a risk I didn't want to take when I was creating the layouts in photoshop, but feel that I should have done.