While not a OBW, mine was a kaleidoscope so assembled the same way only without the fussy cutting. I just sewed a HST to each corner of the octagon to make a square block. The bias edge was what was sewn to the block corner leaving the the corners of the block not on the bias, which IMHO is more desirable and also the way a quilt set on point handles the 4 corners. I had no issues, but I wasn't trying to blend anything either, I used a solid for the corners. Below is a picture of a couple of the blocks.
I actually like your original fabric but really love it as OBW blocks and I think a solid that compliments them in a green or terracotta or deep maroon could be quite striking but would want to audition it before committing to it.
[ATTACH=CONFIG]613175[/ATTACH]