I think you're close ... the colors are just a smidge off, and the organic feel of the mottle doens't play well with the abstract art work.
Here's a couple you might consider
http://www.fabric.com/ProductDetail....0-6a69e3297a79
http://www.fabric.com/ProductDetail....0-6a69e3297a79
http://www.fabric.com/ProductDetail....0-6a69e3297a79
http://www.fabric.com/ProductDetail....0-6a69e3297a79
Oooh ... I think this one would be awesome with your blocks. Perhaps a slightly larger white border, then this print with a wonky mitered corner.
http://www.fabric.com/ProductDetail....e-5fc78630d03e