I typically do all of those things and sort of did here. I did not choose the binding until the quilt was quilted. The binding I was using was one of the fabrics in this scrappy quilt. Even though it was one of the darker colors, it is a happy color. Unfortunately, I trusted my judgment without auditioning it first. I was glad to use it because I have a couple yards of it, so I wouldn't deplete one of my other fabrics to zero. I am silly like that ;-). My instinct was to use a different fabric, but I don't have enough of that one, so I thought, oh, well this will work.
So I let fabric stash-ology rule over design ;-). And now, I guess I have binding for the next kid quilt already cut -- so watch me try and create a whole quilt centered around the rejected binding. I'm like that! And I have a lesson LEARNED ;-).
The color and value of the rejected binding are not wrong, really. They just change the "feel" of the quilt in a way that I didn't want. So next time I'll be thinking about the "feel" I want to obtain, rather than the notion that "this will work because it's one of the fabrics in the quilt." It does work. It doesn't clash. It's just doesn't have the right "it" factor ;-).