Fun fabrics really set these blocks off! Stripes are great fun in them too.
The blocks should come 12.5 inches which makes them 12 inch finished blocks when they are placed into a quilt.
As for red white and blue, just play with the blocks too see. Some of them will look great in just three colors.
I had (until my PC died in a storm two weeks ago) EQ5 and I previewed the blocks and various colors in it.