Your blocks are really great. I am working on a black, gray and white quilt for one of my grandson's. I used a deep, rich red with a little black print as an accent. I love it because it is very masculine and it has the right amount of 'pop'. I can hardly get my other work done because I am anxious to finish it. When I was at my LQS which is not very local I had several prints to choose from. I also thing other colors, the yellow, lime green or even blue would be great. What about two colors in the sashing. You might use one color on the top and one side and the second color on the bottom and second side. You could even vary the right angle positions in some blocks.