Well actually not that long ago! In 1999 I bred my third litter; with access to the information we have now I would not have chosen the pairing. A litter of nine with one born sleeping. The first and third born were blue and I can't tell you how devastated I was. For me it was a disaster, I worried about the stigma and thought I'd have to hide them away. In my mind at the time of birth it was a huge black mark against my line. If you were that way inclined at that time it was not unheard of for non-standard colours to be culled at birth. For us of course that was never a consideration.
As the litter grew we loved them as much as the others, and suddenly I realised well they were there, it was only colour so who cares? Of course blue is a dilute of black and is not a recognised breed colour, so I was extremely careful where I sold them, and I sold them both cheaper than the standard coloured dogs. They had their pedigree's endorsed and I told their owners that I would not be lifting the endorsement. They signed to say they would not breed from them and would neuter them at the correct age. Both sets of owners were true to their word.
Blue puppies darken with age and as adults they are a charcoal colour, there is always a blue tinge to the muzzle, and they usually have very pale tan and yellow eyes. As adults to the layperson they can often look like a normal GSD, but breed enthusiasts would always see the difference. The second photos is Marley who is the blue puppy in the top photo.
Taking that on board I'm sure you understand my contempt at people who are now breeding to produce these colours, blue's, livers, whites etc and selling them at extortionate prices as "Rare" Colours. No not rare, a bloody colour fault. Greed and more greed and never for the good of the breed.
I recently saw a bitch advertised as needing a new home due to a marriage break up. She was pedigree and spayed, but they would not be handing over the papers. Fair enough, until you see that they want 3K for her! Now "back in the day" she would be called a rescue and they'd be lucky to get anything for her. When did it all change? God knows it hasn't changed for the better!