Thank you - everyone - for your responses. One of the things I've learned from this is that there must be a huge difference in the way colors show up on monitors, because to some people the questionable "plum" fabric looked very blue, and to others pinkish. To my eye it has more red tone than blue. I tried to get some more pictures of it and realized that in my camera's viewfinder that fabric looked very, very blue. When transferred to the computer it had more red tones and had become a definite purple, but still not the color it is in real life, under natural light. I never could get it to show up on my monitor as it actually appears.
And yes, the reason I was asking is that I was beginning to regret my fabric choices, particularly the plum, and had been thinking that I really could have used a green somewhere. Great minds must think alike; I just wish mine thought a little quicker. ;-)
I have almost finished the top using these fabrics, and the plum/purple is definitely the zinger. I'm still not sure whether I like it, but done will be done. I'll post pictures when the top and/or the quilting is done, but again I doubt that the colors will be true. I even tried taking the pictures with a different camera, and that came out slightly better. I think you will all have to come to my guild's quilt show (assuming I finish this in time) to decide for yourself whether the plum looks okay in real life. I know I will be standing around listening for comments!