After going back to the topic, I know believe that the "Chocolate/Brown" chick's father is the Silver Braekel, they have autosomal barring, which is ER/ER Db/Db, Pg/Pg
Db is required for the Autosomal barring pattern, but Db stands for Dark brown a columbian restrictor,
D
ark brown Db Incompletely dominant. Changes black down of E, ER to reddish-brown. Adults males exhibit a Columbian-type pattern of black, modifies red to orange-tan. Db is a better restrictor of black in males than females.
I hope that helps