hey Kim, do you have a good black copper boy? If you take those lighter blue girls and cross them onto him for a generation, you will darken up the blue a bit. If it is a bit too dark on those out of that cross, then cross them onto a splash male if you have one. That will back off some of the depth of the blue color, but shouldn't take away the hackle color if the girls are really light blue to begin with.
You can tell I haven't had my coffee yet, cause I totally misunderstood what you were trying to do. if you are tryin to get to lighter girls, then it will be fastest to have a splash male to cross on them. There are other things you can do, but that's the most direct way. This is why I always try to keep a male of each color and females of all three as well. I just love, love, love the way blues work.