Not my idea, i'm just part of this fun class! This is something outside of the norm for me (the part about not knowing how the quilt will look when I'm done and working with colors that I shy away from...)
I think I will put white sashing between the blocks, and use cornerstones that are all the various colors. Then I'll come back for help here and ask about what kind of border to put on. But that will be after the holidays.
Even if you're not part of any BOM Club or if you don't have a BOM pattern book - just use a variety of 12" blocks and pick a new accent color for each one. Close your eyes and have someone hold a tin of crayons in front of you and see what happens.