Do you think with our modern dyes, that washing first is still necessary? I only wash fabric like a red flannel (still needs to be washed again, therefore, no quilt made yet), or a fabric to be used in a "trade block" and was required to have been washed first. I use color catchers and haven't had a problem yet. I've been quilting less than 5 years, but have made about 2 dozen quilt projects, so maybe I'm just lucky.
I prefer to cut unwashed fabric for sewing because I think I cut more accurately, but I (nearly) always wash clothing prior to wearing.