Chances are those babies with the gray color are boys. Every white chick I've hatched with that much gray was a cockeral.
There are some different thoughts on the color you're seeing, one is that's a double silver gene roo and the silver is expressing itself. The newest one is that it might be the lavender gene.
Hang on to that boy, put him with a black girl and see what color you get. You might be seeing the lavender gene.