If the Cock bird used was a Dark IG then crossed with a LS (silver hen) you would get sex linked chicks ie, males white, hens brown.
So wonder what's happened there then
maybe the IG wasn't pure or could have been a Jubilee.
Anyway doesn't matter they look good strong stock
And the LS look nice big utility type.
Nice dark heckles as well
Are you still looking to process at 17-20 weeks ?
And what weight are you looking for?