What this means is your quilt needs color contrast . If it doesn't (and this is speaking from experience), it will look flat. I made a quilt once were the colors were different but they had the same value. I couldn't figure out what was wrong with it. Nothing popped, it looked rather flat. So I read up on color value. Bought myself a color wheel and the little red and green windows you look through and I've had pretty good luck since. Don't know if I'm explaining myself well but if I find a link I'll pass it on. Can any one else add to the subject of value?