2 pens setup like this:
Pen1 (largest pen) - Silver Welbar cockerels that are heterozygous for gold, with silver or gold Welbar pullets and some Cream Legbar pullets.
Pen 2 - Cream Legbars and/or Opal Legbars.
Brown eggs from pen 1 will hatch into autosexing Welbar chicks, about half gold and...