I had a quilt that had a blue backing-washed it several time with no problem. Then one time is bled and turned the white to pale blue. Could never figure it out. Why after washing many times it suddenly bled. I use vinegar in my wash as a normal procedure as we have hard water and it helps the soap to come out as well as any orders and light stains. Worked for my grandmother and it works for me. Even showed my DDIL how to take the mustiness out of her towels.