I saw a demo by the guy that works with Alex Anderson and he picked the ugliest fabrics of all colors and made a quilt. It was beautiful. He did use lights, mediums and darks. Sometimes it is hard to tell whether a fabric is light, medium or dark when you have a grouping. I look at my fabrics with one of those red pieces of plastic. It allows you to see the colors in blacks, whites and grays and makes it much easier to separate the fabrics. You might get a color chart and one of these red pieces of plastic for your friend. Both have helped me with my colors. Sometimes, an ugly fabric is just what the quilt needs to pop.