I used to always use a solid to back all of my quilts..granted I learned to quilt back in the early 1970's as a young girl from my grandma, all by hand, and muslin was the preferred backing.
Fast forward to 5 yrs or so ago, I picked up quilting again. Happened upon a wonderful lqs, and found out pretty much any fabric works for backings, pre wash of course to accommodate shrinking..since fabrics vary.
I now usually use a backing that's a variety of colors/patterns that coordinates with the quilt design. Another big plus of not using plain muslin any more is it helps hide my fmq stitches that aren't so great. Especially since I've only been machine quilting for the last few years.
My dh would laugh if he read this, as he's been know to tease me by saying it looks like I enjoy taking out stitches more than stitching...
Can you post a pic of the quilt top so we can get a better idea?? Plus I love looking at everyone's quilts!
K