Well, I am not keeping any cockerels. All my roosters will be pure bred. Right now I only have 2, but they are from very different lines and 1.5 year apart in age.
The other problem, is with 46 layers, I have no way to know which ones lay light. If you have any suggestions as to how I can know, do tell.
personally I would find being pick about egg color over hatching them all and worrying about hens is way easier. After you have the hen that lays the light egg, you can isolate them one at a time until you find the culpit... or I have heard people using food coloring :yuck