One thing that Feline Fanatic brought up that I think is a very good point - if you are going to do some "out there" quilting, it's best to use a plain backing so the quilting will show. I've put a lighter neutral shade on a black with bright colored top because I was doing a lot of black thread quilting and I did want it to show on the back. A wild print on the back is great if you don't want the quilting to show - there are no seams or corners in the back to hide stops and starts -so all that shows very well.
I do make plenty of quilts that I'm more particular about the backing as they are made for someone specific, but the majority of what I make - I make because i want to and have no idea who is going to end up with it. And it is better to have them finished than "perfect" so when I get a backload of tops (like 10 -15) sitting in a pile, I will pick backing from stash that is good enough and get them out to the LA to get them quilted.