After an hour of mapping out my overall dimensions, determining the patchwork dimensions and then the placement of each fabric, I came up with a satisfactory design. I was not going for a deliberate pattern in the placement of a given colour of fabric. It took a bit of fiddling here and there, but I mapped out 5 rows and then mirrored the balance of the quilt. The 5th row (middle) of the quilt breaks it up enough that you don't see an obvious symmetry.
Next steps...battting, trim and backing. I must make it out to the fabric store to get these in the next few days, though I wish I had them at the moment. I am not sure if I should just bind this quilt in one of the existing fabrics, or if I should just use some eyelet trim. I happened to place this shell of a quilt on top of some washed bed linens the other day. The edge of a white pillow case with eyelet trim was peeking out from the corner and it looked quite lovely!
In the mean time (and to keep the momentum going), I will work on the matching pillow (case). I am just trying to figure out if I want a standard 18"x18" square or if I want to make a 15"x18" rectangle. I am leaning toward the rectangle option... but I will see what options the fabric store has in the way of inserts. Their supply may very well dictate the finished dimensions.