At a stash buster class I was told that it is better not to use all the coordinated fabrics from a group of line of fabrics. But I have trouble seeing colors so that's what I try to buy. I know my greens or watever go together. I think once it is put together you will like it better.
Now, if I really do have make something that is not a favorite - I put in my donate stack. Someone else may just love your quilt!