I think this is what would happen if you took a traditional granny square and gave it a good SHAKE!

This square is inspired by, and the first few rounds are worked the same as, the “Not in the Middle”
Square by Pia Lindén, which can be found here:
http://virkpia.blogspot.se/2013/03/mormorsruta-med-forskjutet-mittparti.html
http://www.ravelry.com/patterns/library/not-in-the-middle---granny

You can join each new color in any corner, to achieve the look you want. I have noted in the pattern which corner I used, if you want one like my picture, but the instructions are the same for any corner. As well, this pattern can be extended to any size by repeating the last three rounds. If you like making huge granny squares for baby blankets, for instance, this pattern would be an interesting one - and different each time you made it, if you want.

Tested by Scraplyn and debspugs, thank you so much!