Yea, almost mentioned crowwing but figured my posts were long enough.. lol Crowwing is also used in standard OEG and longtails.
And then there's Black Copper Marans.. same as brown red/gold birchen/crowwing, etc.
I have a Blue Copper Marans cockerel now. I have a feeling if I said I had a Lemon Blue Marans, I probably would get corrected for that.... yet they are the same really.
IMO the names really need to be standardized more evenly. Fat chance of that ever happening though.
Do you have pictures of your Silver Blues?