I've had this happen to me once where a fabric was a shade off of what I thought it was. So I moved the blocks around until both fabrics were pretty much evenly distributed. It turned out to give the quilt another dimension. You don't notice it first, and the eye keeps wandering around not really noticing the different shades.
I really don't mind ripping. I told my mind that ripping is quilting. Now, I don't get upset if I have to rip. I used to get so annoyed with ripping that it took the pleasure away from working toward an end result.