Argh!  Sometimes you got it, and sometimes you don't.  That first series of compositions sprang forth from my nogging like a geyser.  It was so fun that I thought I'd try it again.  Of course this time I thought I'd get more clever with it, and BLAM!  My creativity slammed head first into a brick wall.  After a few days of stewing on it, I decided I just need to set it free and move on.  I'm sure when I come back to it in a week with fresh eyes, I'll suddenly have all sorts of new ideas for it.  Anyway, here is the unfinished results so far.  As you can see I added a third color, gray, or grey if you prefer.  It allowed me to overlap my shapes, which gave me a new option to create the illusion of depth.