& by waiting 18 months, I'm guessing so you know it's personality will be set? OP, they're not done growing physically/mentally until about 2 years... so I think that's why she is mentioning that.
There are many things to base what dog you chose on, but temperment is definately most important. There are just so many factors, and you have to find a dog that fits in your home. Do you have other pets, does the dog need to get along with cats, will the dog be living with children, how much daily exercize will you be providing, etc etc? So many things factor in and come before color. You could find a beautiful blue dog, but it may not fit your home.
& what she means about issues with blue dogs is that because they're kind of the fad... they're over produced with no regard to health or temperment. So many BYBers are producing them left and right because that's what's selling/demanded. Many times these problems do not show while puppies, and people are so focused on color that the dogs are the ones to suffer later in life.
Amy please correct me, I don't want to sound like I'm trying to put words in your mouth.
Was just hopefully trying to expand reasoning in case they didn't know why you were saying those things. I agree with you 100%