I am not at all sure it would look bad if you wanted to add more colors by adding them as the double sides to the blue bars. If you are consistent in using solids and the some color on both sides of one block, going for a scrappy look just with those solids, might add some real variety and interest.
The other thing that I can see, and I think I would do if they were mine, would be to find all my floral scraps with any hint of those blues that I could do the double strips in, making it a floral scrappy with the blue bar blocks uniting the florals.