Wow, great tutorial and amazing quilt. I think should be able to do a one color tumbling block. But I think you may have to test the value of your fabric and make sure they are distinct enough against each other. If your piles are sorted by light medium and dark there may be some fabrics between the medium and dark that may need to be switched.
This is where one of those red pieces of plastic work great to determine what fabrics will really be of the same value.