Due to many reports confirming this. It's now pretty much confirmed that Silver Sebright carry the autosomal recessive gold diluter cream ig (also known as citron in Europe). It will not come out on the first cross because it's recessive in nature.
I will try to keep this as simple as possible.
Gold Laced Sebright Are: ER/ER, Pg/Pg-Ml/Ml/-Db/Db, Co/Co, s+/s+, Ig+/Ig+
Silver Laced Sebright Are: ER/ER, Pg/Pg-Ml/Ml-Db/Db, Co/Co, S/S, ig/ig
The Citron(Lemon) mutation is actually the autosomal recessive cream ig.
Ig+ = Non-Citron, Wildtype found on Red Jungle Fowl. Autosomal Dominant in nature
ig = Citron/Lemon/Cream, autosomal recessive in nature and diluter of gold.
s+ = recessive sex linked gold
S = Dominant sex linked Silver
s+/s+ and ig/ig = True Citron/Lemon/Cream, both sexes carry it.
S/s+ and Ig+/ig = Golden, very similar in color to true Citron, but it does not breed true, only males can show it.
The F1 cross of Gold Laced male and Silver Laced females will be.
F1 Males: ER/ER, Pg/Pg-MI/MI-Db/Db, Co/Co, S/s+, Ig+/ig = They will look Lemon but not due to Citron, but due to Gold and Silver mixing on the same male.
F1 Females: ER/ER, Pg/Pg-MI/MI-Db/Db, Co/Co, s+/-, Ig+/ig = They will look gold because the females will only inherit their fathers sex linked gold gene and none of their dame Silver and because Ig+ is inhibiting the action of Citron.
You can input that in the Chicken Calculator to get the results of F1 x F1 crossing. You will end up with 25% true Citron.
I hope that is not too technical, I tried my best to simplify it the most I could without losing any important detail.