Octuple Rainbow: Multiplying Spiral

The Octuple Rainbow, 144 squares of gorgeous yarn math and color mixing, is a single unit.  I don't think I can wrap my mind around this concept.

I raced through the last quarter and finished it just on time.  Impressive considering how far behind schedule I was.  I was literally working on it in a movie theatre the day I finished it.  The last stitches were done in the car, in fact, and I let my youngest brother snuggle under it all the way home because I'm nice like that.

Then I took pictures.  Remember the picture of the two stacked quarters offset?  I had to do it again with three.

And then with four.  But you might recall that I was missing one of my quarters because I had loaned it off to my best friend.  So I had to wait until Sunday to retrieve it.  He laughed at me when he saw what I was doing.

Granted, I was wearing a floor-length skirt and tugging blanket pieces around, so I suppose I must have looked fairly ridiculous.  But the shot is pretty!  Not exactly symmetrical, but pretty.

Then all that was left were two long seams.  I did have to do some fancy stitching at the corners to get them to hold together properly, but it turned out nicely if I do say so myself.  My youngest brother and I were watching and mocking the new Teenage Mutant Ninja Turtle cartoons (because we feel they are intelligent enough to watch but ridiculous enough to make fun of) while I sat sewing away.  Ready to see the result?

For reference, each of those squares is approximately the size of a small woman's hand (I'll have to take a picture of how neatly my hand fits into a square).

And yes, this picture is outside.  The shadow in the lower lefthand corner is the old playset in the backyard.  I am precariously perched upon the monkey bars, snapping one-handed pictures.

Only one thing left to do, and that's the border.  Seven rounds in the seven weeks left of the year, and I know the color progression, but I'm not entirely sure on the pattern.  I have at least three ideas floating around in here.  Just have to pick one!