Only a few things left to take care of...

The big deal here is the addition of the dark line around the blue square... it has an anchoring effect on the painting.

For the most part, this is done. I still need to straighten out a few lines, and sign it, but the finished product shouldn't stray too far from this.

Photo includes preliminary sketches I did after planning everything (shapes, position, and color mixing) mentally right before falling asleep the other night!