There's nothing wrong with the way you have the blocks. I'm not one for ripping and re-doing unless I absolutely have to and you certainly don't have to for this quilt to be great. I would definitely add the dark again to the other two sides come back in with a fairly wide red border then back to the dark or if its done enough - bind in the darker color. You can always use any of the different configurations next time you make a log cabin quilt.